Lighting fixture for automated grouping

ABSTRACT

Control of lighting fixtures in a lighting network may be distributed among the lighting fixtures. The lighting fixtures may be broken into groups that are associated with different lighting zones. At least some of the lighting fixtures will have or be associated with one or more sensors. Within the overall lighting network or the various lighting zones, the lighting fixtures may share sensor data from the sensors. Each lighting fixture processes sensor data provided by its own sensor, a remote standalone sensor, or lighting fixture, and processes the sensor data according to the lighting fixture&#39;s internal logic to control operation of the lighting fixture. The lighting fixtures may also receive control input from other lighting fixtures, control nodes, light switches, and commissioning tools. The control input is processed along with the sensor data according to the internal logic to enhance control of the lighting fixture.

This application claims the benefit of U.S. provisional application No.61/738,749 filed Dec. 18, 2012, the disclosure of which is incorporatedherein by reference in its entirety.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to concurrently filed U.S. patentapplication Ser. No. 13/782,040 entitled LIGHTING FIXTURE FORDISTRIBUTED CONTROL, Ser. No. 13/782,053 entitled EFFICIENT ROUTINGTABLES FOR LIGHTING NETWORKS, Ser. No. 13/782,068 entitled HANDHELDDEVICE FOR COMMUNICATING WITH LIGHTING FIXTURES, Ser. No. 13/782,078entitled AUTO COMMISSIONING LIGHTING FIXTURE, Ser. No. 13/782,096entitled MASTER/SLAVE ARRANGEMENT FOR LIGHTING FIXTURE MODULES, and Ser.No. 13/782,131 entitled COMMISSIONING FOR A LIGHTING NETWORK, thedisclosures of which are incorporated herein by reference in theirentireties.

FIELD OF THE DISCLOSURE

The present disclosure relates to lighting fixtures, and in particularto lighting fixtures that are employed in a lighting network.

BACKGROUND

In recent years, a movement has gained traction to replace incandescentlight bulbs with lighting fixtures that employ more efficient lightingtechnologies as well as to replace relatively efficient fluorescentlighting fixtures with lighting technologies that produce a morepleasing, natural light. One such technology that shows tremendouspromise employs light emitting diodes (LEDs). Compared with incandescentbulbs, LED-based light fixtures are much more efficient at convertingelectrical energy into light, are longer lasting, and are also capableof producing light that is very natural. Compared with fluorescentlighting, LED-based fixtures are also very efficient, but are capable ofproducing light that is much more natural and more capable of accuratelyrendering colors. As a result, lighting fixtures that employ LEDtechnologies are expected to replace incandescent and fluorescent bulbsin residential, commercial, and industrial applications.

Unlike incandescent bulbs that operate by subjecting a filament to adesired current, LED-based lighting fixtures require electronics todrive one or more LEDs. The electronics generally include a power supplyand a special control circuitry to provide uniquely configured signalsthat are required to drive the one or more LEDs in a desired fashion.The presence of the control circuitry adds a potentially significantlevel of intelligence to the lighting fixtures that can be leveraged toemploy various types of lighting control.

Lighting control systems for traditional or LED-based lighting fixturesgenerally employ a central controller to control a group of lightingfixtures. The central controller is configured to send commands orsignals to each of the lighting fixtures in the group, and the lightingfixtures will respond to the commands or signals to turn on or off, dimto a desired level, and the like. As such, the lighting controldecisions are made by the central controller based on inputs received bythe central controller, and the lighting fixtures are simply controlledin response to these lighting control decisions.

SUMMARY

The present disclosure relates to a lighting network where control ofthe lighting fixtures in the network may be distributed among thelighting fixtures. The lighting fixtures may be broken into groups thatare associated with different lighting zones. At least some of thelighting fixtures will have or be associated with one or more sensors,such as occupancy sensors, ambient light sensors, and the like. Withinthe overall lighting network or the various lighting zones, the lightingfixtures may share sensor data from the sensors. Each lighting fixturemay process sensor data provided by its own sensor, a remote standalonesensor, or lighting fixture, and process the sensor data according tothe lighting fixture's own internal logic to control operation of thelighting fixture. The lighting fixtures may also receive control inputfrom other lighting fixtures, control nodes, light switches, andcommissioning tools. The control input may be processed along with thesensor data according to the internal logic to further enhance controlof the lighting fixture.

Accordingly, control of the lighting network of the present disclosureis decentralized so that each lighting fixture essentially operatesindependently of the lighting network; however, the internal logic ineach of the lighting fixtures is configured so that the lightingfixtures may act in concert as a group. While acting in concert, eachlighting fixture may operate in a different manner depending on thegoals for the particular lighting application. The lighting fixtures mayalso respond to any user inputs that are presented.

In one embodiment, a lighting fixture having a light sensor, asolid-state light source, and associated circuitry is provided. Thecircuitry is adapted to determine that a given lighting fixture of aplurality lighting fixtures is entering a lightcast mode. Via the lightsensor, the circuitry will monitor for a first lightcast signal providedby the given lighting fixture and effect generation of grouping data forthe given lighting fixture based on receipt of the first lightcastsignal. The grouping data may be used, at least in part, for groupingthe lighting fixture with one or more of the plurality of lightingfixtures. For grouping the lighting fixture with one or more of theplurality of lighting fixtures, the circuitry may send the grouping datato a remote entity, which will determine how to group the plurality oflighting fixtures, and receive information identifying a group to whichthe lighting fixture belongs. Alternatively, the circuitry may send thegrouping data to one of the plurality of lighting fixtures that willdetermine how to group the plurality of lighting fixtures.

For grouping the lighting fixture with one or more of the plurality oflighting fixtures, the circuitry may process the grouping data alongwith other grouping data received from one or more of the pluralitylighting fixtures to determine a group of the plurality of lightingfixtures in which the lighting fixture belongs. If the first lightcastsignal is detected, the grouping data may be indicative of a relativesignal strength of the lightcast signal.

In another embodiment, the circuitry may be adapted to enter thelightcast mode and then drive the solid-state light source to provide asecond lightcast signal to be monitored by the plurality of lightingfixtures. In advance of providing the lightcast signal, the circuitrymay send, to the plurality of lighting fixtures, an instruction to beginmonitoring for the second lightcast signal.

The circuitry may be further adapted to receive remote sensor data fromat least one of the plurality of lighting fixtures and drive thesolid-state light source based on the remote sensor data. As such, thecircuitry may determine local sensor data from the light sensor oranother local sensor of the lighting fixture and drive the solid-statelight source based on both the remote sensor data and the local sensordata. The circuitry may also send the local sensor data to at least oneof the plurality of lighting fixtures.

The circuitry may also identify a group of the plurality of lightingfixtures to which the lighting fixture has been assigned and drive thesolid-state light source in response to an instruction intended for thegroup. Each lighting fixture may be assigned to just one group or may beassigned to multiple groups in the case of overlapping groups, whichshare at least one lighting fixture.

The circuitry may be split into a driver module that is adapted to drivethe solid-state light source and a communications module that is adaptedto communicate with the plurality of lighting fixtures and control thedriver module. The driver module and the communications modulecommunicate with one another over a communications bus.

In yet another embodiment, a lighting network is provided with aplurality of lighting fixtures having associated light sensors. During amonitor mode, each of the plurality of lighting fixtures is adapted todetermine that a given lighting fixture of the plurality lightingfixtures is entering a lightcast mode; via the light sensor, monitor fora lightcast signal provided by the given lighting fixture; and effectgeneration of grouping data for the given lighting fixture based onreceipt of the first lightcast signal. During a receive mode, eachlighting fixture will drive an associated solid-state light source toprovide the lightcast signal for monitoring by others of the pluralityof lighting fixtures. Each of the plurality of lighting fixtures may beautomatically assigned to at least one of a plurality of groups based onthe grouping data.

The grouping data associated with any two of the plurality of lightingfixtures may indicate a relative magnitude of the lightcast signal,which was provided by a first of the two, and received by a second ofthe two. Further, each of the plurality of lighting fixtures may beadapted to exchange the grouping data that is gathered for others of theplurality of lighting fixtures and automatically assign itself to one ofa plurality of groups based on the grouping data, such that each of theplurality of groups comprises those lighting fixtures that were able todetect the lightcast signal from other lighting fixtures in theparticular group. Alternatively, each of the plurality of lightingfixtures may be adapted to exchange the grouping data that is gatheredfor others of the plurality of lighting fixtures and automaticallyassign itself to one of a plurality of groups based on the groupingdata, such that each of the plurality of groups comprises those lightingfixtures that were able to detect, at a magnitude above a set threshold,the lightcast signal from other lighting fixtures in the particulargroup.

The grouping data gathered by each of the plurality of lighting fixturesmay be sent to a remote entity, which assigns the plurality of lightingfixtures to groups based on the grouping data. The grouping datagathered by each of the plurality of lighting fixtures may also be sentto one of the plurality of lighting fixtures, which assigns theplurality of lighting fixtures to groups based on the grouping data.

Also, each lighting fixture may be adapted to share sensor data from itslight sensor or another associated sensor with others of the pluralityof lighting fixtures, and control light output based on the sensor datain light of its own internal logic. The internal logic may be configuredsuch that each of the plurality of lighting fixtures operatesindependently from one another while providing light in a concertedfashion.

In yet another embodiment, a lighting network is provided with a groupof lighting fixtures, which have sensors and solid-state light sources.Each lighting fixture of the group of lighting fixtures may be adaptedto coordinate with at least one of the of the group of lighting fixturesto determine a light output level, and drive the solid-state lightsources to provide the light output. At least certain of the group oflighting fixtures will concurrently provide a different light outputlevel. Different subgroups of the group of lighting fixtures may providedifferent light output levels or output levels that are graduated amongthe group of lighting fixtures. The light output level for each lightingfixture may be determined, at least in part, on ambient light. Theamount of ambient light may be detected via the light sensor of thelighting fixture. Notably, the light output level for each lightingfixture may be determined, at least in part, on an amount of ambientlight detected via a light sensor of another lighting fixture of thegroup of lighting fixtures.

Each of the plurality of lighting fixtures, including the group oflighting fixtures, may be adapted to determine that a given lightingfixture of the plurality of lighting fixtures is entering a lightcastmode; via the light sensor, monitor for a lightcast signal provided bythe given lighting fixture; and effect generation of grouping data forthe given lighting fixture based on receipt of the first lightcastsignal. Each of the plurality of lighting fixtures may drive anassociated solid-state light source to provide the lightcast signal formonitoring by others of the plurality of lighting fixtures. Each of theplurality of lighting fixtures may be automatically assigned to at leastone of a plurality of groups based on the grouping data.

Those skilled in the art will appreciate the scope of the disclosure andrealize additional aspects thereof after reading the following detaileddescription in association with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings incorporated in and forming a part of thisspecification illustrate several aspects of the disclosure, and togetherwith the description serve to explain the principles of the disclosure.

FIG. 1 is a perspective view of a troffer-based lighting fixtureaccording to one embodiment of the disclosure.

FIG. 2 is a cross section of the lighting fixture of FIG. 1.

FIG. 3 is a cross section of the lighting fixture of FIG. 1 illustratinghow light emanates from the LEDs of the lighting fixture and isreflected out through lenses of the lighting fixture.

FIG. 4 illustrates a driver module and a communications moduleintegrated within an electronics housing of the lighting fixture of FIG.1.

FIG. 5 illustrates a driver module provided in an electronics housing ofthe lighting fixture of FIG. 1 and a communications module in anassociated housing coupled to the exterior of the electronics housingaccording to one embodiment of the disclosure.

FIG. 6 illustrates a lighting system for an exemplary floor plan.

FIG. 7 is a table illustrating lightcast data for the lighting systemillustrated in FIG. 6.

FIGS. 8A-8E illustrate exemplary zones for the floor plan illustrated inFIG. 6, when the lightcast process is provided with the doors from eachroom into the hallway open.

FIG. 9 is a communication flow diagram illustrating a grouping processaccording to one embodiment of the present disclosure.

FIG. 10 is a communication flow diagram illustrating the sharing ofsensor data among the lighting fixtures of the lighting system.

FIG. 11 is a communication flow diagram illustrating the sharing ofsensor data and the creation of instructions within the lighting system.

FIG. 12 is a communication flow diagram illustrating both the relay ofinstructions and the ability to modify instructions within the lightingsystem.

FIG. 13A illustrates a lighting system with three distinct zones,wherein each zone may have a different output level based on thepresence of ambient light.

FIG. 13B illustrates a lighting system wherein there is a gradient inthe light output based on the presence of ambient light.

FIG. 14 is a block diagram of a lighting system according to oneembodiment of the disclosure.

FIG. 15 is a cross section of an exemplary LED according to a firstembodiment of the disclosure.

FIG. 16 is a cross section of an exemplary LED according to a secondembodiment of the disclosure.

FIG. 17 is a schematic of a driver module and an LED array according toone embodiment of the disclosure.

FIG. 18 is a block diagram of a communications module according to oneembodiment of the disclosure.

FIG. 19 is a block diagram of a lighting fixture according to a firstembodiment of the disclosure.

FIG. 20 is a block diagram of a lighting fixture according to a secondembodiment of the disclosure.

FIG. 21 is a block diagram of a lighting system wherein thefunctionality of the driver module and the communications module isintegrated.

FIG. 22 is a block diagram of a standalone sensor module according oneembodiment of the disclosure.

FIG. 23 is a block diagram of a commissioning tool according to oneembodiment of the disclosure.

FIG. 24 is a block diagram of a switch module according to oneembodiment of the disclosure.

FIG. 25 is a block diagram of a smart fixture according to oneembodiment of the disclosure.

FIG. 26 is a block diagram of an indoor RF communication module.

FIG. 27 outdoor RF communication module according to one embodiment ofthe disclosure.

FIG. 28 is a block diagram of a lighting fixture comprising a smartfixture and an indoor RF communication module according to oneembodiment of the disclosure.

FIG. 29 is a block diagram of a lighting fixture comprising a smartfixture, an indoor RF communication module, and a fixture sensor moduleaccording to one embodiment of the disclosure.

FIG. 30 is a block diagram of a wireless sensor according to oneembodiment of the disclosure.

FIG. 31 is a block diagram of a wireless relay module that is capable ofdriving a legacy fixture according to one embodiment of the disclosure.

FIG. 32 is a block diagram of a wireless switch according to oneembodiment of the disclosure.

FIG. 33 is a communication flow diagram illustrating an iterativeprocess for selecting a coordinator according to one embodiment of thedisclosure.

FIG. 34 is a communication flow diagram illustrating an iterativeprocess for selecting a coordinator according to another embodiment ofthe disclosure.

FIGS. 35A-35C are communication flow diagrams illustrating an iterativeprocess for selecting a coordinator according to another embodiment ofthe disclosure.

FIG. 36 is a block diagram of an exemplary lighting fixture according toone embodiment of the disclosure.

FIG. 37 illustrates a routing diagram for a first lighting systemconfiguration.

FIG. 38 illustrates a routing diagram for a second lighting systemconfiguration.

FIG. 39 illustrates a routing diagram for a third lighting systemconfiguration.

FIG. 40 is an alternative lighting fixture configuration according to asecond embodiment of the disclosure.

DETAILED DESCRIPTION

The embodiments set forth below represent the necessary information toenable those skilled in the art to practice the disclosure andillustrate the best mode of practicing the disclosure. Upon reading thefollowing description in light of the accompanying drawings, thoseskilled in the art will understand the concepts of the disclosure andwill recognize applications of these concepts not particularly addressedherein. It should be understood that these concepts and applicationsfall within the scope of the disclosure and the accompanying claims.

It will be understood that relative terms such as “front,” “forward,”“rear,” “below,” “above,” “upper,” “lower,” “horizontal,” or “vertical”may be used herein to describe a relationship of one element, layer orregion to another element, layer or region as illustrated in thefigures. It will be understood that these terms are intended toencompass different orientations of the device in addition to theorientation depicted in the figures.

The present disclosure relates to a lighting network where control ofthe lighting fixtures in the network may be distributed among thelighting fixtures. The lighting fixtures may be broken into groups thatare associated with different lighting zones. At least some of thelighting fixtures will have or be associated with one or more sensors,such as occupancy sensors, ambient light sensors, and the like. Withinthe overall lighting network or the various lighting zones, the lightingfixtures may share sensor data from the sensors. Each lighting fixturemay process sensor data provided by its own sensor, a remote standalonesensor, or lighting fixture, and process the sensor data according tothe lighting fixture's own internal logic to control operation of thelighting fixture. The lighting fixtures may also receive control inputfrom other lighting fixtures, control nodes, light switches, andcommissioning tools. The control input may be processed along with thesensor data according to the internal logic to further enhance controlof the lighting fixture.

Accordingly, control of the lighting network of the present disclosuremay be decentralized so that each lighting fixture essentially operatesindependently of the lighting network; however, the internal logic ineach of the lighting fixtures is configured so that the lightingfixtures may act in concert as a group. While acting in concert, eachlighting fixture may operate in a different manner depending on thegoals for the particular lighting application. The lighting fixtures mayalso respond to any user inputs that are presented.

For example, a switch may be used to turn on all of the lightingfixtures in a particular zone. However, the amount of light provided bythe various lighting fixtures may vary from one lighting fixture to thenext based on the amount of ambient light present or the relativeoccupancy in the different areas of the lighting zone. The lightingfixtures closer to windows may provide less light or light of adifferent color or color temperature than those lighting fixtures thatare near an interior wall. Further, lighting fixtures closer to peopleor those proximate to larger groups of people may provide more light orlight of a different color or color temperature relative to the otherlighting fixtures. For example, in a long hallway, the presence of anoccupant could not only turn on the hallway group of lighting fixtures,but could also dictate dimming levels for the various fixtures so thatthe whole hallway is lit with a low light level while the area (orareas) immediately around the occupant (or occupants) has a higher lightlevel. The areas with more occupants could have higher light output thanthose with fewer or more occupants. The speed of travel could alsodictate relative light output levels.

Traditional lighting control systems rely on a central controller tomake all decisions and control the various lighting fixtures from afar.The distributed control approach of the present disclosure is not solimited. While a central controller may be employed, the commands fromthe central controller may be treated as a suggestion or just anotherinput to be considered by each lighting fixture's internal logic.Particularly unique to the present disclosure is the ability to sharesensor data between lighting fixtures. Being able to share sensor dataallows otherwise independently functioning lighting fixtures to act as agroup in a coordinated fashion.

For example, each lighting fixture in a lighting zone may take its ownambient light reading, but rather than acting only on its own ambientlight reading, the ambient light reading is shared with the otherlighting fixtures in the group. When all of the light fixtures in thelighting zone have shared their ambient light readings, each lightingfixture can independently determine an average or a minimum light outputbased on the ambient light readings from the entire group. As such, thelighting fixtures in the group will adjust their output consistentlywith one another while operating independently from one another.

Prior to delving into the details of the present disclosure, an overviewof an exemplary lighting fixture in which the distributed lightingcontrol system may be employed is described. While the concepts of thepresent disclosure may be employed in any type of lighting system, theimmediately following description describes these concepts in atroffer-type lighting fixture, such as the lighting fixture 10illustrated in FIGS. 1-3. While the disclosed lighting fixture 10employs an indirect lighting configuration wherein light is initiallyemitted upward from a light source and then reflected downward, directlighting configurations may also take advantage of the concepts of thepresent disclosure. In addition to troffer-type lighting fixtures, theconcepts of the present disclosure may also be employed in recessedlighting configurations, wall mount lighting configurations, outdoorlighting configurations, and the like. Reference is made to co-pendingand co-assigned U.S. patent application Ser. No. 13/589,899 filed Aug.20, 2013, Ser. No. 13/649,531 filed Oct. 11, 2012, and Ser. No.13/606,713 filed Sep. 7, 2012, the contents of which are incorporatedherein by reference in their entireties. Further, the functionality andcontrol techniques described below may be used to control differenttypes of lighting fixtures, as well as different groups of the same ordifferent types of lighting fixtures at the same time.

In general, troffer-type lighting fixtures, such as the lighting fixture10, are designed to mount in a ceiling. In most applications, thetroffer-type lighting fixtures are mounted into a drop ceiling (notshown) of a commercial, educational, or governmental facility. Asillustrated in FIGS. 1-3, the lighting fixture 10 includes a square orrectangular outer frame 12. In the central portion of the lightingfixture 10 are two rectangular lenses 14, which are generallytransparent, translucent, or opaque. Reflectors 16 extend from the outerframe 12 to the outer edges of the lenses 14. The lenses 14 effectivelyextend between the innermost portions of the reflectors 16 to anelongated heat sink 18, which functions to join the two inside edges ofthe lenses 14.

Turning now to FIGS. 2 and 3 in particular, the back side of theheatsink 18 provides a mounting structure for an LED array 20, whichincludes one or more rows of individual LEDs mounted on an appropriatesubstrate. The LEDs are oriented to primarily emit light upwards towarda concave cover 22. The volume bounded by the cover 22, the lenses 14,and the back of the heatsink 18 provides a mixing chamber 24. As such,light will emanate upwards from the LEDs of the LED array 20 toward thecover 22 and will be reflected downward through the respective lenses14, as illustrated in FIG. 3. Notably, not all light rays emitted fromthe LEDs will reflect directly off of the bottom of the cover 22 andback through a particular lens 14 with a single reflection. Many of thelight rays will bounce around within the mixing chamber 24 andeffectively mix with other light rays, such that a desirably uniformlight is emitted through the respective lenses 14.

Those skilled in the art will recognize that the type of lenses 14, thetype of LEDs, the shape of the cover 22, and any coating on the bottomside of the cover 22, among many other variables, will affect thequantity and quality of light emitted by the lighting fixture 10. Aswill be discussed in greater detail below, the LED array 20 may includeLEDs of different colors, wherein the light emitted from the variousLEDs mixes together to form a white light having a desired colortemperature and quality based on the design parameters for theparticular embodiment.

As is apparent from FIGS. 2 and 3, the elongated fins of the heatsink 18may be visible from the bottom of the lighting fixture 10. Placing theLEDs of the LED array 20 in thermal contact along the upper side of theheatsink 18 allows any heat generated by the LEDs to be effectivelytransferred to the elongated fins on the bottom side of the heatsink 18for dissipation within the room in which the lighting fixture 10 ismounted. Again, the particular configuration of the lighting fixture 10illustrated in FIGS. 1-3 is merely one of the virtually limitlessconfigurations for lighting fixtures 10 in which the concepts of thepresent disclosure are applicable.

With continued reference to FIGS. 2 and 3, an electronics housing 26 isshown mounted at one end of the lighting fixture 10, and is used tohouse all or a portion of the electronics used to power and control theLED array 20. These electronics are coupled to the LED array 20 throughappropriate cabling 28. With reference to FIG. 4, the electronicsprovided in the electronics housing 26 may be divided into a drivermodule 30 and a communications module 32.

At a high level, the driver module 30 is coupled to the LED array 20through the cabling 28 and directly drives the LEDs of the LED array 20based on control information provided by the communications module 32.The driver module 30 provides the intelligence for the lighting fixture10 and is capable of driving the LEDs of the LED array 20 in a desiredfashion. The driver module 30 may be provided on a single, integratedmodule or divided into two or more sub-modules depending the desires ofthe designer.

The communications module 32 acts as an intelligent communicationinterface that facilitates communications between the driver module 30and other lighting fixtures 10, a remote control system (not shown), ora portable handheld commissioning tool, which may also be configured tocommunicate with a remote control system in a wired or wireless fashion.The commissioning tool is referred to herein as a commissioning tool 36,which may be used for a variety of functions, including thecommissioning of a lighting network. As noted above, thesecommunications may include the sharing of sensor data, instructions, andany other data between the various lighting fixtures 10 in the lightingnetwork. In essence, the communications module 32 functions tocoordinate the sharing of intelligence and data among the lightingfixtures 10.

In the embodiment of FIG. 4, the communications module 32 may beimplemented on a separate printed circuit board (PCB) than the drivermodule 30. The respective PCBs of the driver module 30 and thecommunications module 32 may be configured to allow the connector of thecommunications module 32 to plug into the connector of the driver module30, wherein the communications module 32 is mechanically mounted, oraffixed, to the driver module 30 once the connector of thecommunications module 32 is plugged into the mating connector of thedriver module 30.

In other embodiments, a cable may be used to connect the respectiveconnectors of the driver module 30 and the communications module 32,other attachment mechanisms may be used to physically couple thecommunications module 32 to the driver module 30, or the driver module30 and the communications module 32 may be separately affixed to theinside of the electronics housing 26. In such embodiments, the interiorof the electronics housing 26 is sized appropriately to accommodate boththe driver module 30 and the communications module 32. In manyinstances, the electronics housing 26 provides a plenum rated enclosurefor both the driver module 30 and the communications module 32.

With the embodiment of FIG. 4, adding or replacing the communicationsmodule 32 requires gaining access to the interior of the electronicshousing 26. If this is undesirable, the driver module 30 may be providedalone in the electronics housing 26. The communications module 32 may bemounted outside of the electronics housing 26 in an exposed fashion orwithin a supplemental housing 34, which may be directly or indirectlycoupled to the outside of the electronics housing 26, as shown in FIG.5. The supplemental housing 34 may be bolted to the electronics housing26. The supplemental housing 34 may alternatively be connected to theelectronics housing snap-fit or hook-and-snap mechanisms. Thesupplemental housing 34, alone or when coupled to the exterior surfaceof the electronics housing 26, may provide a plenum rated enclosure.

In embodiments where the electronics housing 26 and the supplementalhousing 34 will be mounted within a plenum rated enclosure, thesupplemental housing 34 may not need to be plenum rated. Further, thecommunications module 32 may be directly mounted to the exterior of theelectronics housing 26 without any need for a supplemental housing 34,depending on the nature of the electronics provided in thecommunications module 32, how and where the lighting fixture 10 will bemounted, and the like. The latter embodiment wherein the communicationsmodule 32 is mounted outside of the electronics housing 26 may provebeneficial when the communications module 32 facilitates wirelesscommunications with the other lighting fixtures 10, the remote controlsystem, or other network or auxiliary device. In essence, the drivermodule 30 may be provided in the plenum rated electronics housing 26,which may not be conducive to wireless communications. Thecommunications module 32 may be mounted outside of the electronicshousing 26 by itself or within the supplemental housing 34 that is moreconducive to wireless communications. A cable may be provided betweenthe driver module 30 and the communications module 32 according to adefined communication interface.

The embodiments that employ mounting the communications module 32outside of the electronics housing 26 may be somewhat less costeffective, but provide significant flexibility in allowing thecommunications module 32 or other auxiliary devices to be added to thelighting fixture 10, serviced, or replaced. The supplemental housing 34for the communications module 32 may be made of a plenum rated plasticor metal, and may be configured to readily mount to the electronicshousing 26 through snaps, screws, bolts, or the like, as well as receivethe communications module 32. The communications module 32 may bemounted to the inside of the supplemental housing 34 through snap-fits,screws, twistlocks, and the like. The cabling and connectors used forconnecting the communications module 32 to the driver module 30 may takeany available form, such as with standard category 5 (cat 5) cablehaving RJ45 connectors, edge card connectors, blind mate connectorpairs, terminal blocks and individual wires, and the like. Having anexternally mounted communications module 32 relative to the electronicshousing 26 that includes the driver module 30 allows for easy fieldinstallation of different types of communications modules 32 for a givendriver module 30.

In one embodiment, the capabilities of the lighting fixtures 10 allowthem to be readily grouped into different lighting zones. With referenceto FIG. 6, assume that there are 18 ceiling mounted lighting fixtures10, which are uniquely referenced as lighting fixtures A through R andplaced in different rooms RM₁ through RM₄ and hallway HW₁ of floor planFP₁.

In particular, lighting fixture A resides in room RM₁; lighting fixturesB-E reside in room RM₂; lighting fixtures I, J, L, M, Q, and R reside inroom RM₃; lighting fixtures N and O reside in room RM₄, and lightingfixtures F, G, H, K, and P reside in hallway HW₁. Assuming that thedoors from the hallway HW₁ into each of the respective rooms RM₁-RM₄ areclosed, lighting fixtures A-R may be grouped into five unique lightingzones using a lightcast procedure. During a lightcast procedure, onelight fixture A-R will adjust or modulate its light output while theother lighting fixtures A-R attempt to monitor or detect the adjusted ormodulated light output of the first lighting fixture A-R.

Assume that the modulated or adjusted lightcast signal is a visible ornear visible, such as infrared, light signal, which can be detected bythe ambient light sensors that are provided in or associated with thevarious lighting fixtures A-R. Initially, assume lighting fixture Aemits the visible or near visible lightcast signal, while the rest ofthe lighting fixtures B-R monitor their ambient light sensors to detectthe relative strength of the lightcast signal being received by theintegrated or associated ambient light sensors. Again assuming that thedoor between room RM₁ and the hallway HW₁ is closed, none of the otherlighting fixtures A-R will detect the lightcast signal provided bylighting fixture A, and thus lighting fixture A will be grouped alone.Next, lighting fixture B will provide a lightcast signal, and lightingfixtures A and C-R will begin monitoring for the lightcast signal beingprovided by lighting fixture B. In this instance, lighting fixture Cwill detect the lightcast signal relatively strongly, lighting fixture Dwill detect the lightcast signal more weakly, and lighting fixture Ewill detect a faint lightcast signal, if the lightcast signal isdetected at all.

A relative magnitude may be assigned to the lightcast signal monitoredby each of the lighting fixtures C-E. These magnitudes may be used topopulate a table, such as that illustrated in FIG. 7, or a portionthereof that is pertinent for to a specific lighting fixture A-R. Inthis example, the lightcast signal emitted by lighting fixture B isassigned a relative strength of 0.7 for a range of 0 to 1.0 by lightingfixture C, 0.3 by lighting fixture D, and 0.1 by lighting fixture E.Since the door between room RM₂ and the hallway HW₁ is closed, none ofthe other lighting fixtures A or F-R will be able to detect thelightcast signal from lighting fixture B.

Next, lighting fixture C will begin providing the lightcast signal andthe other lighting fixtures A, B, and D-R will begin monitoring for thelightcast signal provided by lighting fixture C. Lighting fixtures B, D,and E in room RM₂ will detect the lightcast signal and assign a relativemagnitude for the lightcast signal. The magnitudes are provided in FIG.7. Again, lighting fixtures A and F-R will not detect the lightcastsignal due to their relative locations. This process is systematicallyrepeated for each of the remaining lighting fixtures D-R such that thetable of FIG. 7 is fully populated. By analyzing the signal strengthmagnitudes of the various lighting fixtures A-R, one can readily dividethe various groups of lighting fixtures A-R into associated lightingzones. Visually, one can readily determine that lighting fixture Ashould be in a zone by itself, lighting fixtures B-E should be in asecond zone, lighting fixture I, J, L, M, Q, and R should be in a thirdzone, lighting fixtures N and O should be in a fourth zone, and lightingfixtures F, G, H, K, and P should be in a fifth zone. Each of thesezones directly corresponds to the placement of the various lightingfixtures A-R in rooms RM₁-RM₄ and the hallway HW₁. In additional tosimply grouping the lighting fixtures A-R of the different rooms intocorresponding zones, one can readily determine the relative proximityand placement of the various lighting fixtures A-R with respect to eachother based on the relative magnitudes of the lightcast signals.

As described further below, the various lighting fixtures A-R may alsomonitor RF signals strengths from the one another. The RF signalstrength between the various lighting fixtures A-R can be used todetermine the distance between and relative location of lightingfixtures A-R. Further, the relative distance between and location ofgroups with respect to one another may be determined. As such, arelative distance and location can be determined for every fixture inthe RF network and any groups thereof using the lightcast signal, RFsignal strength, or a combination thereof. The results can be used togenerate a scaled map of the lighting fixtures A-R and other elements inthe lighting network. The map may include the commissioning tool 36 aswell. In addition to using RF signal strength, microphones and speakerscould be used in association with or instead of lightcasting techniquesfor grouping, communications, and the like. Each lighting fixture A-Rcould have or be associated with a microphone, or like acoustic (sonicor ultrasonic) sensor, and an audio amplifier and speaker (sonic orultrasonic).

The microphones would allow the lighting fixture to pick up voicecommands, like “brighter,” “dimmer,” “on,” or “off,” (or other acousticdata, perhaps footsteps for occupancy) and process the acousticinformation. The information may cause the lighting fixture to controlthe light source in a desired fashion, issue commands to other lightingfixtures A-R (or other nodes), or share the acoustic information withother lighting fixtures A-R (or other nodes). A network of distributedmicrophones provided by the lighting fixtures A-R or in associationtherewith could determine not only things like where sounds are comingfrom (is the user in the same room?), but which direction and how fastthe source of the sounds is moving (if the user is hurrying toward theexit, or even yelling “fire,” maybe there's an emergency and the spaceshould be more well-lit for safety reasons).

There is also the capability to provide a network of noise suppressingor noise canceling lighting fixtures all working together to keep officespaces quiet. The speakers may be driven with white or pink noise, whichis configured to reduce the impact of ambient noise. For true noisecanceling, the ambient noise monitored by the microphones at one or agroup of the lighting fixtures A-R could be inverted (or played out ofphase with respect to the ambient noise) and played back with thecorresponding speakers at a volume that will provide a noise cancelingeffect for nearby occupants.

Notably, each lighting fixture A-R may generate its own table, as shownin FIG. 7, or a portion thereof. For example, each lighting fixture A-Rmay simply maintain an array that stores the relative magnitudes of thelightcast signals from the other lighting fixtures A-R. In thisinstance, each of the lighting fixtures A-R will respond to commands andshare data with only those lighting fixtures A-R from which a lightcastsignal was detected at all or detected above a certain magnitude. Inthese instances, each lighting fixture A-R can effectively associateitself with a zone. Alternatively, all of the lightcast signal data maybe delivered to a master lighting fixture 10, which is capable ofcollecting all of the data for the table of FIG. 7, analyzing the data,assigning each of the lighting fixtures A-R to various zones, andcommunicating the zoning information to the lighting fixtures A-R.Further, the processing provided by the master lighting fixture 10 couldalso be outsourced to a remote control entity, such as the commissioningtool 36, or a central control system.

In the prior example, all of the doors in the hallway HW₁ were closed.As such, grouping the various lighting fixtures A-R into the fivedifferent zones was relatively clear cut, wherein all of the lightingfixtures in a room RM₁-RM₄ or the hallway HW₁ were grouped intodifferent zones. As such, none of the lighting fixtures A-R wereassigned to more than one zone.

However, it may be desirable to have certain lighting fixtures A-Rassigned to more than one zone. As an example, if the door into room RM₁is normally open, it may be desirable to have lighting fixtures F and G,which are in the hallway HW₁, associated in some fashion with the zonefor room RM₁, which includes lighting fixture A. Continuing with thisconcept, when lighting fixture A is providing the lightcast signal,lighting fixtures F and G of the hallway HW₁ may detect the lightcastsignal. Similarly, when lighting fixtures F and G are providing alightcast signal, they may pick up each others' lightcast signal, andlighting fixture A may also pick up the lightcast signals of lightingfixtures F and G. As such, respective lighting fixtures A, F, and G, oranother control entity, will analyze the lightcast signal informationand associate lighting fixtures A, F, and G with zone Z₁ as illustratedin FIG. 8A. If all of the doors in the hallway HW₁ remain open, thelightcast process may continue such that lighting fixtures B, C, D, andE of room RM₂ are grouped with lighting fixtures G, H, and K of hallwayHW₁ in zone Z₂ as illustrated in FIG. 8B. Similarly, the lightingfixtures I, J, L, M, Q, and R of room RM₃ may also be associated withlighting fixtures G, H, and K of hallway HW₁ in zone Z₃, as shown inFIG. 8C. Lighting fixtures N and O of room RM₄ may be associated withlighting fixtures F and G of hallway HW₁ for zone Z₄, as illustrated inFIG. 8D.

With reference to the hallway HW₁, when the doors are all open, thelighting fixtures H, G, K, and P may be associated with various lightingfixtures A, B, C, I, L, N, and O of the various rooms RM₁-RM₄. If thisis not desired, a user may modify the grouping of the various lightingfixtures A-R such that just the lighting fixtures F, G, H, K, and P areassociated with zone Z₄, which represents the lighting for just thehallway HW₁, as illustrated in FIG. 8E. Accordingly, the automaticgrouping of the lighting fixtures 10 can be readily modified throughdirect interaction with each of the lighting fixtures 10 or from aremote control entity, such as the commissioning tool 36. Furtherdetails with respect to how the lighting fixtures 10 communicate witheach other, share data, and operate in a concerted fashion are providedfurther below.

With reference to FIG. 9, a partial communication flow is provided toillustrate an exemplary lightcast process and the functionality of eachlighting fixture 10 involved in the process. The operation of lightingfixtures B-D, which are assumed to be in the same room, is highlighted.Initially, lighting fixture B decides to enter the lightcast mode basedon an instruction from lighting fixture A or some other control entity(step 100). Deciding to enter the lightcast mode may be triggeredinternally, from an external input over a wired or wireless network, oroptically in response to receiving a lightcast signal with a certainsignature. For example, lighting fixture B may enter a lightcast modebased on the time of day, periodically, based on sensor readings, or inresponse to a manual (user) request. Alternatively, the lightcast signalmay always be monitored for, and may take the form of a specific off/onsignature or modulation of the light, which gets automatically detectedand measured by the monitoring light fixture 10.

Upon entering the lightcast mode, lighting fixture B will send aninstruction out to the other lighting fixtures 10 directly or via abroadcast signal to look for a lightcast signal from lighting fixture B.Notably, these instructions may be sent directly from one lightingfixture 10 to another or may be relayed from one lighting fixture 10 toanother throughout the lighting fixture network. As illustrated, theinstructions to look for the lightcast signal provided by lightingfixture B is received by lighting fixture C (step 102) and relayed tolighting fixture D (step 104). However, instructions may be sentdirectly to lighting fixture D from lighting fixture B without beingrelayed.

At this point, both lighting fixtures C and D will begin monitoring forthe lightcast signal to be provided by lighting fixture B (steps 106 and108). Accordingly, lighting fixture B will begin adjusting or modulatingits light source in some fashion to provide the lightcast signal (step110). Notably, the lightcast signal is an optical signal that will notbe relayed from one lighting fixture 10 to another. Instead, lightingfixtures C and D will detect and process the lightcast signal togenerate the grouping data (steps 112 and 114). The grouping data mayrange from simply determining whether or not the lightcast signal isdetected or detected above a given threshold to assigning a relativemagnitude to the lightcast signal, as discussed in association with thetable of FIG. 7. After a certain amount of time, lighting fixture B willstop providing the lightcast signal (step 116) and provide instructionsfor lighting fixture C to enter the lightcast mode (step 118).Alternatively, a remote controlling entity, such as the commissioningtool 36, may provide instructions to lighting fixture C to enter thelightcast mode. At this point, lighting fixture C will decide to enterlightcast mode (step 120) and the process will repeat for lightingfixture C. This sequence of events will continue for each of thelighting fixtures 10 in the lighting network.

With regard to processing the lightcast signals, the lightcast signalmeasurements, which are monitored by the receiving lighting fixtures 10,may be associated with an ID of the sending lighting fixture 10, thereceiving lighting fixture 10, or both. The sending lighting fixture 10may be identified based on an ID provided in the message to look for alightcast signal (in step 110) or a unique modulation signal that eitherincludes the ID of the sending lighting fixture 10 or that is associatedwith the lighting fixture 10. The associations may be done by internalor remote control systems. Further, associations could be made based ontime stamping or synchronizing the sending of lightcast signals by thedifferent lighting fixtures 10 so that the sending lighting fixture 10can be associated with the lightcast signal measurements from thevarious receiving fixtures 10.

The receiving lighting fixtures 10 may report the lightcast signalmeasurements along with the associated IDs of the receiving lightingfixtures 10 and the synchronizing or identifying information that can beused to associate the lightcast signal with a particular sendinglighting fixture 10. Timestamping or other sensor information may beincluded in such a measurement report. These types of lightcastmeasurement reports can be used to develop tables of information, suchas that shown in FIG. 7, for different times and include other sensorparameters. As such, greater granularity is provided into the control ofthe lighting fixtures 10 or light groupings, wherein the type of controlcan change at different times and/or based on different inputs from thesensors. For instance, control may change once an hour or when certainsensor readings are monitored.

Throughout this process or at the end of the process, each of thelighting fixtures 10 will either exchange the grouping data or providethe grouping data to a master lighting fixture 10 or a remote controlentity to process the grouping data and assign the various lightingfixtures 10 to corresponding zones (step 122). In a primarilydistributed control process, the internal logic provided in each of thelighting fixtures 10 will allow the lighting fixtures 10 to effectivelyassign themselves to an appropriate zone based on the grouping data.Once a lighting fixture 10 has been assigned to a zone or has identifieditself as being associated with a group of lighting fixtures 10, variousinformation may be exchanged between the lighting fixtures 10 within agiven zone. This information may range from sensor data to instructionsfor controlling operation.

Lightcast techniques may also be used to detect occupancy or lackthereof. The lighting fixtures 10 (and any other lightcast capabledevices) may be configured to periodically or relatively continuouslyproviding lightcasting, perhaps in a manner not visible or perceptibleto the human eye, to compare lightcast readings relative to an emptyroom. Changes in the reference lightcast readings may indicate thepresence of occupants, the amount of change may be indicative of thenumber of occupants, and the locations of the changes may be indicativeof the location of the occupants. A return to the reference lightcastreading may indicate the area has been vacated, thus potentiallyeliminating the need to check for vacancy using traditional body heat ormotion sensors.

Notably, acknowledgments may be provided in response to eachcommunication signal or message as well as upon detecting a lightcastsignal. These acknowledgements may be provided over the wired orwireless networks that support inter-lighting fixture communications, ormay be provided optically using a type of lightcast signal having acertain modulation signature that is indicative of an acknowledgement.The acknowledgement signals or other response signals may be used toexchange status, signal strength information, requests for additionalinformation, and the like. Within a given lighting system, differentcommunication techniques (wired, wireless, lightcast modulation) may beused for different types of communications, data/information exchange,control, and the like. Communications may also be provided over AC powerlines using conventional techniques.

With reference to FIG. 10, a partial communication flow is provided toillustrate how sensor data may be exchanged among the various lightingfixtures 10 within a zone or a lighting network in general. Assume thatlighting fixtures B, C, and D have been assigned to a particular zone.During operation, lighting fixtures B, C, and D will monitor andexchange sensor data and collectively use the sensor data to determinehow to adjust their respective light outputs. Initially, lightingfixture B will monitor its sensor data, which is data from an associatedambient light, occupancy, or other sensor (step 200). Lighting fixture Bwill send its sensor data to the other lighting fixtures C and D in thezone (step 202). Meanwhile, lighting fixture C is monitoring its sensordata (step 204) and providing the sensor data to lighting fixtures B andD (step 206). Similarly, lighting fixture D is monitoring its sensordata and (step 208) and providing the sensor data to lighting fixtures Cand B (step 210). Thus, each of the lighting fixtures B, C, and D hasaccess to its own sensor data and the sensor data of the other lightingfixtures in its zone. While this example is zone-oriented, all of thelighting fixtures 10 in the entire lighting network may be providing allsensor data to one another or certain sensor data or all or certain onesof the lighting fixtures 10 in the lighting network. Within a givenzone, a group of fixtures may separate themselves into one or moreseparate (or sub) zones if their ambient light sensors detect more lightthan the rest of the lighting fixtures in the zone. This couldcorrespond to a group of lights that are closest to the window.

In a relatively continuous fashion, lighting fixture B will process thesensor data from its own sensor and the sensor data from the otherlighting fixtures C and D (step 212) and determine how to adjust itslight output based on the sensor data (step 214). Accordingly, lightingfixture B is independently controlling its light output; however, theinternal logic of lighting fixture B may take into consideration notonly its own sensor data but the sensor data of the other lightingfixtures C and D when determining precisely how to adjust its lightoutput. In an independent yet concerted fashion, lighting fixtures C andD will also process their sensor data and the sensor data from the otherlighting fixtures, and adjust their light output based on the sensordata (steps 216-222).

Interestingly, the internal logic of the different lighting fixtures B,C, and D may be configured to function identically to one another ordifferently from one another. For example, lighting fixtures B, C, and Dmay apply the same weighting to the sensor data as the other lightingfixtures B, C, and D in the zone. Thus, given the same sensor data fromits own sensor and from the other lighting fixtures B, C, and D, eachlighting fixture B, C, and D will adjust its light output in exactly thesame fashion. If the internal logic varies among the lighting fixturesB, C, and D, the light output of the respective lighting fixtures B, C,and D may vary given the same sensor data. Notably, the sensor data mayinclude data from different types of sensors. For example, sensor datafrom both ambient light and occupancy sensors may be exchanged andprocessed as dictated by the internal logic of each lighting fixture B,C, and D to determine how to adjust their respective light outputs.

In addition to exchanging sensor data and controlling operation in viewthereof, the lighting fixtures B, C, and D may also use their own sensordata as well as the sensor data received from other lighting fixtures B,C, and D to control operation of other lighting fixtures B, C, and D.With reference to FIG. 11, a partial communication flow is shown toillustrate this concept. Initially, assume that lighting fixture B andlighting fixture D are gathering sensor data from their respectivesensors and providing that sensor data to lighting fixture C (steps 300and 302). While not illustrated, lighting fixture C may be providing itssensor data to the other lighting fixtures B and D. Lighting fixture Cmay also be monitoring its own sensor data (step 304), and processingthe sensor data from its own sensor as well as the sensor data from theother lighting fixtures B and D (step 306) to generate instructions forlighting fixtures B and C (step 308). Once the instructions aregenerated, they may be provided to the respective lighting fixtures Band D (steps 310 and 312). Accordingly, lighting fixture B may adjustits light output based on the instructions provided from lightingfixture C, the sensor data of lighting fixture D, or a combinationthereof, depending on the internal logic of lighting fixture B (step314). Lighting fixture C may adjust its light output based on its ownsensor data or a combination of its own sensor data and the sensor datareceived from lighting fixtures B and D (step 316). Like lightingfixture B, lighting fixture D may adjust its light output based oninstructions received from lighting fixture C, sensor data from lightingfixture D, or a combination thereof (step 318).

As a practical example, lighting fixtures B, C, and D may share ambientlight information, which may dictate the intensity of the light output,the color temperature of the light output, the color of the lightoutput, or any combination thereof. However, lighting fixture C may alsobe associated with an occupancy sensor. As such, the instructionsprovided by lighting fixture C to lighting fixtures B and D may instructlighting fixtures B and D to turn on and provide light output at acertain level, color temperature, or color. Lighting fixtures B and Dmay respond directly to these instructions or may process theseinstructions in light of their respective internal logic to determinewhether to turn on and how to control the respective light outputs. Assuch, the instructions provided from one lighting fixture 10 to anothermay be taken as an absolute command and responded to accordingly, or maybe taken as a mere “suggestion” depending on the programming of thelighting fixture 10 that receives the instructions. For example, in thescenario above wherein lighting fixture C is instructing lightingfixture B to turn on, there may be sufficient sunlight measured atlighting fixture B that negates the need for lighting fixture B to turnon. Or, if lighting fixture B does decide to turn on, the color,intensity, or color temperature of the light may be adjusted by theamount and color of the sunlight being measured at lighting fixture B.Again, the distributed control described in the present disclosureallows these lighting fixtures 10 to operate independently, yet inconcert if the internal logic so dictates.

As shown in the partial communication flow of FIG. 12, the instructionsprovided from one lighting fixture 10 to another may be relayed throughan intermediate lighting fixture 10. Further, the instructions may bemodified as they are passed from one lighting fixture 10 to another,based on internal logic, sensor data, or the like. Initially, assumethat lighting fixture A, a commissioning tool 36, or some other controlpoint, switch, or node provides instructions to lighting fixture B (step400). Lighting fixture B may receive these instructions and pass theunmodified instructions on to one or more other lighting fixtures 10such as lighting fixture C (step 402). Lighting fixture B may thenmonitor its own sensor data (step 404), process the sensor data (step406), and generate modified instructions for the other lighting fixtures10, including lighting fixture C, based on its own sensor data, thesensor data of others, the instructions provided, or a combinationthereof (step 408). The modified instructions may be sent to the otherlighting fixtures 10, such as lighting fixture C (step 410). Lightingfixture B can then adjust its light output based on its own sensor data,the sensor data of others, and the instructions received (step 418).Lighting fixture C may monitor its own sensor data (step 412), processits sensor data (step 414), and then adjust its light output based onthe various sensor data, the modified instructions, the unmodifiedinstructions, or a combination thereof (step 416). Through this abilityto share sensor data, communicate with each other, and operateindependently according to internal logic, the various lighting fixtures10 provide tremendous flexibility to lighting configurators.

With reference to FIGS. 13A and 13B, a floor plan FP2 with lightingfixtures A-R is illustrated. In FIG. 13A, the lighting fixtures A-R maybe grouped such that the six lighting fixtures A, B, G, H, M, and N thatare farthest from the windowed end of the room are at their full lightoutputs when on, the six lighting fixtures C, D, I, J, O, and P in themiddle of the room are producing an intermediate light output when on,and the six lighting fixtures E, F, K, L, Q, and R that are closest tothe windows are producing the least amount of light output when on andsunlight is detected by one of more of the lighting fixtures A-R. Inthis instance, the portion of the room with the most ambient sunlightwill employ the least amount of artificial light. Each of the lightingfixtures A-R is associated with an overall zone for the room anddifferent sub-zones for each of the three sets of six lighting fixturesA-R. While the lighting fixtures A-R are broken into three groupsproviding three distinct light output levels when ambient sunlight isdetected, the lighting fixtures A-R may be configured such that everyone of the lighting fixtures A-R provides light output at a differentintensity (or color and color temperature) when ambient sunlight isdetected.

For example and with reference to FIG. 13B, each of the lightingfixtures A-R may be treated as being in the same zone, yet the lightoutput is subject to a gradient that occurs across the entire zone. Thegradient may be linear or non-linear. For example, lighting fixture M,which is farthest away from any of the windows, will provide the mostlight output, while lighting fixture F, which is likely to be in an areareceiving the most ambient sunlight, will provide the least lightoutput.

Each of the lighting fixtures between lighting fixtures M and F mayprovide a continuously decreasing amount of light output according to adefined linear or non-linear gradient that is shared amongst thelighting fixtures A-R. Notably, the gradient may be known by all of thelighting fixtures A-R, wherein the gradient is continuously adjustedbased on the amount of ambient sunlight available. Thus, the effectiveslope of the gradient is greatest when lighting fixture F detects thegreatest amount of ambient sunlight, wherein the light outputdifferential between the lighting fixtures M and F is the greatest. Atnight, when there is no ambient sunlight and very little light, if any,being received through the windows, all of the lighting fixtures A-R maydetermine to provide the same amount of light output, based on thoselighting fixtures A-R that are closest to the windows sharing ambientlight sensor data with the other lighting fixtures A-R in the zone.Again, the lighting fixtures A-R are capable of acting independentlybased on their own or shared sensor data. The internal logic used tocontrol the light output based on the various sensor data may be fixed,manually adjusted, or dynamically adjusted based on interaction amongthe lighting fixtures A-R.

With continued reference to FIGS. 13A and 13B, assume that a doorway(not shown) is located near lighting fixture A and that at leastlighting fixture A has or is associated with an occupancy sensor S_(O).Further assume that all, or at least numerous ones of the lightingfixtures A-R have or are associated with ambient light sensors S_(A) andare currently in an off state. When someone walks into the room throughthe doorway into the room, the occupancy sensor S_(O) will provide anoccupied signal, which will alert lighting fixture A that the room isnow occupied. In response, lighting fixture A may be programmed toinstruct all of the other lighting fixtures B-R to turn on.Alternatively, lighting fixture A may share its occupancy sensor (orother sensor) information with the other lighting fixtures B-R, whichwill independently use their own internal logic to process the occupancysensor information and turn themselves on.

Alternatively, lighting fixture A may instruct only a subgroup that isassociated with a zone to turn. In the latter case, lighting fixture Amay be programmed to only instruct lighting fixtures A, B, G, H, M, andN to turn on. The other zones [C, D, I, J, O, P] and [E, F, K, L, Q, R]in the room may turn on only when occupancy sensors S_(O) associatedwith those zones detect an occupant. In either case, all of the lightingfixtures A-R may monitor the amount of ambient light being receivedthrough the windows, and perhaps the doorway, and individually controlthe level, color, and color temperature of the light to output onceturned on. The level, color, and color temperature may dynamicallychange as ambient light levels change.

Instead of being instructed to turn on by another lighting fixture, eachof the lighting fixtures A-R may have or be associated with an occupancysensor S_(O) and react independently to detecting an occupant. Theoccupancy sensor S_(O) may employ any available type of motion, heat, orlike sensor technology that is capable of detecting movement or thepresence of people. The lighting fixtures A-R could also be programmedto turn on when light from another lighting fixture A-R is detected.Thus, when lighting fixture A turns on in response to detecting anoccupant, the other lighting fixtures B-R will detect the presence oflight from lighting fixture A and turn on in response to detecting thelight from lighting fixture A turning on.

In certain embodiments, only one of the lighting fixtures A-R needs tobe wired or wirelessly coupled to an on/off switch or dimmer. Iflighting fixture A is coupled to the switch or dimmer, lighting fixtureA can instruct the other lighting fixtures to turn on (as well as dim toa certain level). Alternatively, lighting fixture A could simply turn onto a certain output level. The other lighting fixtures B-R would detectthe light as a result of lighting fixture A turning on, and perhaps therelative level of dimming through an associated ambient light sensorS_(A), and turn on to a certain output level. If not sensed, therelative dimming level could be shared with lighting fixtures B-R bylighting fixture A.

The intelligence of the network is virtually limitless and affords thepotential for highly intelligent lighting systems. For example, thelighting fixtures A-R may be able to determine (or be programmed with)their relative location to one another. Using the occupancy sensorsS_(O), the collective group of lighting fixtures A-R may be configuredto develop predictive algorithms based on historical occupancy data anduse these predictive algorithms to determine how long to keep lights on,what lights should turn on as a person walks into a room or down ahallway, and the like. For instance, the lighting fixtures 10 along ahallway may turn on sequentially and well in advance of a person walkingdown the hallway. The lights may turn off sequentially and behind theperson as well. The sequential turning on of the lights may be triggeredby a first lighting fixture 10 detecting the person, but the remaininglighting fixtures 10 in the hallway may sequentially turn on based onthe historical walking speeds, paths, and the like that are embodied inthe predictive algorithms. Each of the lighting fixtures 10 may sharesensor data, instructions, and the like and then operate independentlyin light of this shared information.

The above concept of “light tracking” is illustrated below with twoexamples. For the first example, reference is made to FIG. 8A, whichprovides a light tracking example for a person walking along the hallwayHW₁. Assume that the person enters the hallway near lighting fixture F,and exits the hallway near lighting fixture P. Also assume that each ofthe lighting fixtures F, G, H, K, and P include occupancy sensors S_(O).As the person enters the hallway near lighting fixture F, lightingfixture F will sense the presence of the person via its occupancy sensorS_(O) and turn itself on. Lighting fixture F may be programmed to alertlighting fixture G that lighting fixture F has detected a user. Lightingfixture G may know that lighting fixture H is currently off, and sincelighting fixture F is detecting the presence of a person, lightingfixture G may turn itself on in a predictive fashion. If lightingfixture G subsequently detects the presence of a person, it may alertlighting fixture H and lighting fixture F. Once lighting fixture Hreceives an indication that the occupancy sensor of lighting fixture Ghas detected a person, it may turn on. If lighting fixture H detects thepresence of a person through its occupancy sensor S_(O), it may alertlighting fixture K, lighting fixture G, and lighting fixture F. Lightingfixture F may take this information as an indication that the person istravelling along the hallway HW₁ toward lighting fixture P, and thusturn off, as it may no longer be needed. Lighting fixture G may remainon for the time being, while lighting fixture K will turn on in apredictive fashion. This process may continue such that one, two, ormore lights are on in the hallway HW₁ near the current location of theperson. The time between adjacent occupancy sensor detections can alsobe used to approximate the speed at which the person is traveling. Thiscan be used to predict where the person or object is going. For example,if someone is slowing down to enter a room, then the lights in the roommay react accordingly.

Further, the ability of the lights to communicate with each other and toshare their occupancy sensor information allows the group of lightingfixtures in the hallway HW₁ to light the current location of the personand predictively turn on lighting fixtures in advance of the personreaching a particular lighting fixture. Of course, all of the lightingfixtures in the hallway HW₁ could be turned on when lighting fixture Fdetects the presence of a person, and turn off when none of the lightingfixtures F, G, H, K, and P detect the presence of a person after acertain amount of time. As yet another tracking example, each of thelighting fixtures F, G, H, K, and P may merely turn on when they detectthe presence of a person and turn off after a certain amount of time ofno longer detecting the presence of a person or when none of thelighting fixtures in the group detects the presence of a person.

The tracking concepts are equally applicable to larger areas, such asrooms or outdoor areas. Reference is made to FIG. 13A or 13B for thefollowing example. In a simplistic example, each of the lightingfixtures A-R may include an occupancy sensor S_(O) and be programmed asfollows. If the occupancy sensor S_(O) for a particular lighting fixtureA-R detects the presence of a person, that lighting fixture will turn onand instruct immediately adjacent lighting fixtures to turn on if theyare not already on. As such, different ones of the lighting fixtures A-Ror groups thereof may turn on and track the people in the room. Thelighting fixture that detected the presence of a person (as well asthose fixtures that were instructed to turn on by that lighting fixture)may stay on for a set period of time after the presence of the person isno longer detected. While the prior example is a simplistic tracking ofroom occupants and selectively turning lighting fixtures on or off basedthereon, predictive algorithms may also be employed. For example, assumea person enters the room near lighting fixture M and walks diagonallyacross the room to the opposing corner near lighting fixture F. Whenlighting fixture M detects the presence of the person, it may turn onand instruct lighting fixtures G, H, and N to turn on. The remaininglighting fixtures will remain off. If lighting fixture N subsequentlydetects the presence of the person, it will remain on and will instructlighting fixtures I and O to turn on, because it knows that lightingfixture M first detected the person and now lighting fixture N isdetecting the person. When lighting fixture I detects the person, it mayalert lighting fixtures B, C, D, H, J, N, O, and P to turn on as well,and may alert lighting fixture M as well. Lighting fixture M may nolonger detect the presence of a person and may turn off, based on theknowledge that it is no longer detecting the presence of a person, andthat lighting fixtures N and I have subsequently detected the presenceof the person. This process may continue across the room, as lightingfixtures J, K, E, L, and F progressively turn on as lighting fixtures M,H, N, and the like turn off after the person has left the correspondingarea of the room. Thus, basic tracking and predictive control may beused in virtually any environment to selectively turn on and turn off orotherwise control lighting fixtures in a room, group, or the like.

Turning now to FIG. 14, a block diagram of a lighting fixture 10 isprovided according to one embodiment. Assume for purposes of discussionthat the driver module 30, communications module 32, and LED array 20are ultimately connected to form the core of the lighting fixture 10,and that the communications module 32 is configured to bidirectionallycommunicate with other lighting fixtures 10, the commissioning tool 36,or other control entity through wired or wireless techniques. In thisembodiment, a standard communication interface and a first, or standard,protocol are used between the driver module 30 and the communicationsmodule 32. This standard protocol allows different driver modules 30 tocommunicate with and be controlled by different communications modules32, assuming that both the driver module 30 and the communicationsmodule 32 are operating according to the standard protocol used by thestandard communication interface. The term “standard protocol” isdefined to mean any type of known or future developed, proprietary orindustry-standardized protocol.

In the illustrated embodiment, the driver module 30 and thecommunications module 32 are coupled via a communication (COMM) bus 38and a power (PWR) bus 40. The communication bus 38 allows thecommunications module 32 to receive information from the driver module30 as well as control the driver module 30. An exemplary communicationbus 38 is the well-known inter-integrated circuitry (I²C) bus, which isa serial bus and is typically implemented with a two-wire interfaceemploying data and clock lines.

Other available buses include: serial peripheral interface (SPI) bus,Dallas Semiconductor Corporation's 1-Wire serial bus, universal serialbus (USB), RS-232, Microchip Technology Incorporated's UNI/O®, and thelike.

In this embodiment, the driver module 30 is configured to collect datafrom the ambient light sensor S_(A) and the occupancy sensor S_(O) anddrive the LEDs of the LED array 20. The data collected from the ambientlight sensor S_(A) and the occupancy sensor S_(O) as well as any otheroperational parameters of the driver module 30 may be shared with thecommunications module 32. As such, the communications module 32 maycollect data about the configuration or operation of the driver module30 and any information made available to the driver module 30 by the LEDarray 20, the ambient light sensor S_(A), and the occupancy sensorS_(O). The collected data may be used by the communications module 32 tocontrol how the driver module 30 operates, may be shared with otherlighting fixtures 10 or control entities, or may be processed togenerate instructions that are sent to other lighting fixtures 10.

The communications module 32 may also be controlled in whole or in partby a remote control entity, such as the commissioning tool 36 or anotherlighting fixture 10. In general, the communications module 32 willprocess sensor data and instructions provided by the other lightingfixtures 10 or remote control entities and then provide instructionsover the communication bus 38 to the driver module 30. An alternativeway of looking at it is that the communications module 32 facilitatesthe sharing of the system's information, including occupancy sensing,ambient light sensing, dimmer switch settings, etc., and provides thisinformation to the driver module 30, which then uses its own internallogic to determine what action(s) to take. The driver module 30 willrespond by controlling the drive current or voltages provided to the LEDarray 20 as appropriate. An exemplary command set for a hypotheticalprotocol is provided below.

Exemplary Command Set

Command Source Receiver Description On/Off Communications Driver ModuleOn/Off Module Color Communications Driver Module Color temperature ofsolid Temperature Module state light Dimming Level Communications DriverModule Set light level Module Fixture ID Driver Module CommunicationsSolid State light id Module Health Driver Module Communications Healthof solid state light Module Power Usage Driver Module CommunicationsPower used by solid state Module light Usage Driver ModuleCommunications Hours of use Module Lifetime Driver Module CommunicationsUseful life (factors hours, Module ambient temp and power level) Zone IDDriver Module Communications Identifies the zone the Module fixture isin Temperature Driver Module Communications Solid State temperatureModule level (protection) Emergency Driver Module CommunicationsIndentifies the fixture as Enabled Module an emergency enabled fixture.Emergency Driver Module Communications Battery State Health ModuleEmergency Communications Driver Module Remote method to allow TestModule testing of emergency solid state fixture Emergency Driver ModuleCommunications Pass indication for Pass Module emergency test EmergencyDriver Module Communications Battery time left time remaining ModuleOccupancy Driver Module Communications Number of occupancy StatisticsModule events Daylighting Driver Module Communications Average dim levelto statistics Module maintain ambient light level Sensor Data Any Devicewith Any Device Ambient light level, Update Sensor(s) occupancydetection status, etc. User Dimmer/Switch Fixtures & Value of dimmerswitch Dimmer/Switch Wireless Relay setting Setting Update Modules

The above table has four columns: command, source, receiver, anddescription. The command represents the actual instruction passed eitherfrom the communications module 32 to the driver module 30 or from thedriver module 30 to the communications module 32. The source identifiesthe sender of the command. The receiver identifies the intendedrecipient of the command. The communication column provides adescription of the command. For example, the “on/off” command is sent bythe communications module 32 to the driver module 30 and effectivelyallows the communications module 32 to instruct the driver module 30 toeither turn on or turn off the LED array 20. The “color temperature”command allows the communications module 32 to instruct the drivermodule 30 to drive the LED array 20 in a manner to generate a desiredcolor temperature. The “color temperature” command may actually includethe desired color temperature or a reference to available colortemperature.

The “dimming level” command is sent from the communications module 32 tothe driver module 30 to set an overall light level based on a desiredlevel of dimming. The “fixture ID” command allows the driver module 30to identify itself to the communications module 32. The “health” commandallows the driver module 30 to send the communications module 32information relative to its operational capability or, in other words,health. The “power usage” command allows the driver module 30 to tellthe communications module 32 how much power is being used by the drivermodule 30 on average or at any given time, depending on the capabilitiesof the driver module 30. The “usage” command allows the driver module 30to identify the total hours of use, hours of consistent use, or the liketo the communications module 32. The “lifetime” command allows thedriver module 30 to provide an estimate of the useful remaining life ofthe driver module 30, the LED array 20, or a combination thereof to thecommunications module 32. Based on the capabilities of the driver module30, the amount of remaining life may factor in past usage, ambienttemperatures, power levels, or the like.

The “zone ID” command allows the driver module 30 to tell thecommunications module 32 in which zone the driver module 30 resides.This command is useful when the other lighting fixtures 10 or the remotecontrol entity is controlling multiple lighting fixtures and iscollecting information about the zones in which the lighting fixtures 10reside. The “temperature” command allows the driver module 30 to provideambient temperature information for the driver module 30 or the LEDarray 20 to the communications module 32.

The “emergency enabled” command allows the driver module 30 to tell thecommunications module 32 that the lighting fixture 10 is an emergencyenabled fixture, which can be used for emergency lighting. The“emergency health” command allows the driver module 30 to provideinformation bearing on the ability of the driver module 30 or thelighting fixture 10 to function as an emergency lighting fixture. In asimple embodiment, the command may provide the state of an emergencybackup battery that has been made available to drive the lightingfixture 10 in case of an emergency. The “emergency test” command allowsthe communications module 32 to send an instruction to the driver module30 to run an emergency lighting test to ensure that the lighting fixture10 can operate in an emergency lighting mode, if so required. The“emergency pass” command allows the driver module 30 to inform thecommunications module 32 that the emergency test was passed (or failed).The above commands primarily describe the direction of information flow.However, the protocol may allow the communications module 32 or thedriver module 30 to selectively or periodically request any of this orother information specifically or in batches.

The use of a standard communication interface and a standard protocolfor communications between the driver module 30 and the communicationsmodule 32 supports a modular approach for the driver module 30 and thecommunications module 32. For example, different manufacturers may makedifferent communications modules 32 that interface with a particulardriver module 30. The different communications modules 32 may beconfigured to drive the driver module 30 differently based on differentlighting applications, available features, price points, and the like.As such, the communications module 32 may be configured to communicatewith different types of driver modules 30. Once a communications module32 is coupled to a driver module 30, the communications module 32identifies the type of driver module 30 and will interface with thedriver module 30 accordingly. Further, a driver module 30 may be able tooperate over various ranges for different lighting parameters. Differentcommunications modules 32 may be configured to control these parametersto varying degrees. The first communications module 32 may only be givenaccess to a limited parameter set, wherein another communications module32 may be given access to a much greater parameter set. The table belowprovides an exemplary parameter set for a given driver module 30.

Parameters

PWM dimming Frequency 200 Hz through 1000 Hz Maximum Light Level 50% to100% Color Temperature 2700 K to 6000 K Maximum allowable hours 50,000to 100,000 Minimum dimming level 0 to 50% Response time 100 ms to 1 secColor temperature settable 0 or 1 Dimming curve Linear, exponential. Dimto warmer or cooler color temperature Alarm Indication 0 or 1

The parameters in the above table may represent the available controlpoints for a given driver module 30. A given parameter set may beassigned to the driver module 30 during manufacture or may be set by thecommunications module 32 during installation of the lighting fixture 10or upon associating the communications module 32 with the driver module30. The parameter set includes various parameters, such as the pulsewidth modulation (PWM) dimming frequency, maximum light level, and colortemperature. The parameter set represents the allowable ranges for eachof these parameters. Each parameter may be set within the identifiedrange in the parameter set during operation or the like by thecommunications module 32 or the remote control system, depending on thedesires of the designer or the particular application.

As an example, the maximum light level for the exemplary parameter setindicates it can be set from anywhere from 50% to 100% of thecapabilities of the driver module 30 and the associated LED array 20. Ifthe end user or owner of the lighting system that employs the lightingfixture 10 initiates the appropriate instructions, the maximum lightlevel may be set to 80% in an appropriate parameter field. As such, thedriver module 30 would not drive the LED array 20 to exceed 80%, even ifthe communications module 32 provided a command to the driver module 30to increase the lighting level above 80% of its maximum capability.These parameters may be stored in the driver module 30 or in thecommunications module 32 in non-volatile memory.

In certain embodiments, the driver module 30 includes sufficientelectronics to process an alternating current (AC) input signal (AC IN)and provide an appropriate rectified or direct current (DC) signalsufficient to power the communications module 32, and perhaps the LEDarray 20. As such, the communications module 32 does not requireseparate AC-to-DC conversion circuitry to power the electronics residingtherein, and can simply receive DC power from the driver module 30 overthe power bus 40, which may be separate from the communication bus 38 ormay be integrated with the communication bus 38, as will be describedbelow.

In one embodiment, one aspect of the standard communication interface isthe definition of a standard power delivery system. For example, thepower bus 40 may be set to a low voltage level, such as 5 volts, 12volts, 24 volts, or the like. The driver module 30 is configured toprocess the AC input signal to provide the defined low voltage level andprovide that voltage over the power bus 40, thus the communicationsmodule 32 or auxiliary devices may be designed in anticipation of thedesired low voltage level being provided over the power bus 40 by thedriver module 30 without concern for connecting to or processing an ACsignal to a DC power signal for powering the electronics of thecommunications module 32.

A description of an exemplary embodiment of the LED array 20, drivermodule 30, and the communications module 32 follows. As noted, the LEDarray 20 includes a plurality of LEDs, such as the LEDs 42 illustratedin FIGS. 15 and 16. With reference to FIG. 15, a single LED chip 44 ismounted on a reflective cup 46 using solder or a conductive epoxy, suchthat ohmic contacts for the cathode (or anode) of the LED chip 44 areelectrically coupled to the bottom of the reflective cup 46. Thereflective cup 46 is either coupled to or integrally formed with a firstlead 48 of the LED 42. One or more bond wires 50 connect ohmic contactsfor the anode (or cathode) of the LED chip 44 to a second lead 52.

The reflective cup 46 may be filled with an encapsulant material 54 thatencapsulates the LED chip 44. The encapsulant material 54 may be clearor contain a wavelength conversion material, such as a phosphor, whichis described in greater detail below. The entire assembly isencapsulated in a clear protective resin 56, which may be molded in theshape of a lens to control the light emitted from the LED chip 44.

An alternative package for an LED 42 is illustrated in FIG. 16 whereinthe LED chip 44 is mounted on a substrate 58. In particular, the ohmiccontacts for the anode (or cathode) of the LED chip 44 are directlymounted to first contact pads 60 on the surface of the substrate 58. Theohmic contacts for the cathode (or anode) of the LED chip 44 areconnected to second contact pads 62, which are also on the surface ofthe substrate 58, using bond wires 64. The LED chip 44 resides in acavity of a reflector structure 65, which is formed from a reflectivematerial and functions to reflect light emitted from the LED chip 44through the opening formed by the reflector structure 65. The cavityformed by the reflector structure 65 may be filled with an encapsulantmaterial 54 that encapsulates the LED chip 44. The encapsulant material54 may be clear or contain a wavelength conversion material, such as aphosphor.

In either of the embodiments of FIGS. 15 and 16, if the encapsulantmaterial 54 is clear, the light emitted by the LED chip 44 passesthrough the encapsulant material 54 and the protective resin 56 withoutany substantial shift in color. As such, the light emitted from the LEDchip 44 is effectively the light emitted from the LED 42. If theencapsulant material 54 contains a wavelength conversion material,substantially all or a portion of the light emitted by the LED chip 44in a first wavelength range may be absorbed by the wavelength conversionmaterial, which will responsively emit light in a second wavelengthrange. The concentration and type of wavelength conversion material willdictate how much of the light emitted by the LED chip 44 is absorbed bythe wavelength conversion material as well as the extent of thewavelength conversion. In embodiments where some of the light emitted bythe LED chip 44 passes through the wavelength conversion materialwithout being absorbed, the light passing through the wavelengthconversion material will mix with the light emitted by the wavelengthconversion material. Thus, when a wavelength conversion material isused, the light emitted from the LED 42 is shifted in color from theactual light emitted from the LED chip 44.

For example, the LED array 20 may include a group of BSY or BSG LEDs 42as well as a group of red LEDs 42. BSY LEDs 42 include an LED chip 44that emits bluish light, and the wavelength conversion material is ayellow phosphor that absorbs the blue light and emits yellowish light.Even if some of the bluish light passes through the phosphor, theresultant mix of light emitted from the overall BSY LED 42 is yellowishlight. The yellowish light emitted from a BSY LED 42 has a color pointthat falls above the Black Body Locus (BBL) on the 1931 CIE chromaticitydiagram wherein the BBL corresponds to the various color temperatures ofwhite light.

Similarly, BSG LEDs 42 include an LED chip 44 that emits bluish light;however, the wavelength conversion material is a greenish phosphor thatabsorbs the blue light and emits greenish light. Even if some of thebluish light passes through the phosphor, the resultant mix of lightemitted from the overall BSG LED 42 is greenish light. The greenishlight emitted from a BSG LED 42 has a color point that falls above theBBL on the 1931 CIE chromaticity diagram wherein the BBL corresponds tothe various color temperatures of white light.

The red LEDs 42 generally emit reddish light at a color point on theopposite side of the BBL as the yellowish or greenish light of the BSYor BSG LEDs 42. As such, the reddish light from the red LEDs 42 mixeswith the yellowish or greenish light emitted from the BSY or BSG LEDs 42to generate white light that has a desired color temperature and fallswithin a desired proximity of the BBL. In effect, the reddish light fromthe red LEDs 42 pulls the yellowish or greenish light from the BSY orBSG LEDs 42 to a desired color point on or near the BBL. Notably, thered LEDs 42 may have LED chips 44 that natively emit reddish lightwherein no wavelength conversion material is employed. Alternatively,the LED chips 44 may be associated with a wavelength conversionmaterial, wherein the resultant light emitted from the wavelengthconversion material and any light that is emitted from the LED chips 44without being absorbed by the wavelength conversion material mixes toform the desired reddish light.

The blue LED chip 44 used to form either the BSY or BSG LEDs 42 may beformed from a gallium nitride (GaN), indium gallium nitride (InGaN),silicon carbide (SiC), zinc selenide (ZnSe), or like material system.The red LED chip 44 may be formed from an aluminum indium galliumnitride (AlInGaP), gallium phosphide (GaP), aluminum gallium arsenide(AlGaAs), or like material system. Exemplary yellow phosphors includecerium-doped yttrium aluminum garnet (YAG:Ce), yellow BOSE (Ba, O, Sr,Si, Eu) phosphors, and the like. Exemplary green phosphors include greenBOSE phosphors, Lutetium aluminum garnet (LuAg), cerium doped LuAg(LuAg:Ce), Maui M535 from Lightscape Materials, Inc. of 201 WashingtonRoad, Princeton, N.J. 08540, and the like. The above LED architectures,phosphors, and material systems are merely exemplary and are notintended to provide an exhaustive listing of architectures, phosphors,and materials systems that are applicable to the concepts disclosedherein.

As noted, the LED array 20 may include a mixture of red LEDs 42 andeither BSY or BSG LEDs 42. The driver module 30 for driving the LEDarray 20 is illustrated in FIG. 17 according to one embodiment of thedisclosure. The LED array 20 may be electrically divided into two ormore strings of series connected LEDs 42. As depicted, there are threeLED strings S1, S2, and S3. For clarity, the reference number “42” willinclude a subscript indicative of the color of the LED 42 in thefollowing text where ‘R’ corresponds to red, ‘BSY’ corresponds to blueshifted yellow, ‘BSG’ corresponds to blue shifted green, and ‘BSX’corresponds to either BSG or BSY LEDs. LED string S1 includes a numberof red LEDs 42 _(R), LED string S2 includes a number of either BSY orBSG LEDs 42 _(BSX), and LED string S3 includes a number of either BSY orBSG LEDs 42 _(BSX). The driver module 30 controls the current deliveredto the respective LED strings S1, S2, and S3. The current used to drivethe LEDs 42 is generally pulse width modulated (PWM), wherein the dutycycle of the pulsed current controls the intensity of the light emittedfrom the LEDs 42.

The BSY or BSG LEDs 42 _(BSX) in the second LED string S2 may beselected to have a slightly more bluish hue (less yellowish or greenishhue) than the BSY or BSG LEDs 42 _(BSX) in the third LED string S3. Assuch, the current flowing through the second and third strings S2 and S3may be tuned to control the yellowish or greenish light that iseffectively emitted by the BSY or BSG LEDs 42 _(BSX) of the second andthird LED strings S2, S3. By controlling the relative intensities of theyellowish or greenish light emitted from the differently hued BSY or BSGLEDs 42 _(BSX) of the second and third LED strings S2, S3, the hue ofthe combined yellowish or greenish light from the second and third LEDstrings S2, S3 may be controlled in a desired fashion.

The ratio of current provided through the red LEDs 42 _(R) of the firstLED string S1 relative to the currents provided through the BSY or BSGLEDs 42 _(BSX) of the second and third LED strings S2 and S3 may beadjusted to effectively control the relative intensities of the reddishlight emitted from the red LEDs 42 _(R) and the combined yellowish orgreenish light emitted from the various BSY or BSG LEDs 42 _(BSX). Assuch, the intensity and the color point of the yellowish or greenishlight from BSY or BSG LEDs 42 _(BSX) can be set relative to theintensity of the reddish light emitted from the red LEDs 42 _(R). Theresultant yellowish or greenish light mixes with the reddish light togenerate white light that has a desired color temperature and fallswithin a desired proximity of the BBL.

Notably, the number of LED strings Sx may vary from one to many anddifferent combinations of LED colors may be used in the differentstrings. Each LED string Sx may have LEDs 42 of the same color,variations of the same color, or substantially different colors, such asred, green, and blue. In one embodiment, a single LED string may beused, wherein the LEDs in the string are all substantially identical incolor, vary in substantially the same color, or include differentcolors. In another embodiment, three LED strings Sx with red, green, andblue LEDs may be used, wherein each LED string Sx is dedicated to asingle color. In yet another embodiment, at least two LED strings Sx maybe used, wherein different colored BSY LEDs are used in one of the LEDstrings Sx and red LEDs are used in the other of the LED strings Sx.

The driver module 30 depicted in FIG. 17 generally includes rectifierand power factor correction (PFC) circuitry 66, conversion circuitry 68,and control circuitry 70. The rectifier and power factor correctioncircuitry 66 is adapted to receive an AC power signal (AC IN), rectifythe AC power signal, and correct the power factor of the AC powersignal. The resultant signal is provided to the conversion circuitry 68,which converts the rectified AC power signal to a DC power signal. TheDC power signal may be boosted or bucked to one or more desired DCvoltages by DC-DC converter circuitry, which is provided by theconversion circuitry 68. Internally, the DC power signal may be used topower the control circuitry 70 and any other circuitry provided in thedriver module 30.

The DC power signal is also provided to the power bus 40, which iscoupled to one or more power ports, which may be part of the standardcommunication interface. The DC power signal provided to the power bus40 may be used to provide power to one or more external devices that arecoupled to the power bus and separate form the driver module 30. Theseexternal devices may include the communications module 32 and any numberof auxiliary devices, which are discussed further below. Accordingly,these external devices may rely on the driver module 30 for power andcan be efficiently and cost effectively designed accordingly. Therectifier and PFC circuitry 66 and the conversion circuitry 68 of thedriver module 30 are robustly designed in anticipation of being requiredto supply power to not only its internal circuitry and the LED array 20,but also to supply power to these external devices as well. Such adesign greatly simplifies the power supply design, if not eliminatingthe need for a power supply, and reduces the cost for these externaldevices.

As illustrated, the DC power signal may be provided to another port,which will be connected by the cabling 28 to the LED array 20. In thisembodiment, the supply line of the DC power signal is ultimately coupledto the first end of each of the LED strings S1, S2, and S3 in the LEDarray 20. The control circuitry 70 is coupled to the second end of eachof the LED strings S1, S2, and S3 by the cabling 28. Based on any numberof fixed or dynamic parameters, the control circuitry 70 mayindividually control the pulse width modulated current that flowsthrough the respective LED strings S1, S2, and S3 such that theresultant white light emitted from the LED strings S1, S2, and S3 has adesired color temperature and falls within a desired proximity of theBBL. Certain of the many variables that may impact the current providedto each of the LED strings S1, S2, and S3 include: the magnitude of theAC power signal, the resultant white light, ambient temperature of thedriver module 30 or LED array 20. Notably, the architecture used todrive the LED array 20 in this embodiment is merely exemplary, as thoseskilled in the art will recognize other architectures for controllingthe drive voltages and currents presented to the LED strings S1, S2, andS3.

In certain instances, a dimming device controls the AC power signal. Therectifier and PFC circuitry 66 may be configured to detect the relativeamount of dimming associated with the AC power signal and provide acorresponding dimming signal to the control circuitry 70. Based on thedimming signal, the control circuitry 70 will adjust the currentprovided to each of the LED strings S1, S2, and S3 to effectively reducethe intensity of the resultant white light emitted from the LED stringsS1, S2, and S3 while maintaining the desired color temperature. Dimminginstructions may alternatively be delivered from the communicationsmodule 32 to the control circuitry 70 in the form of a command via thecommunication bus 38.

The intensity or color of the light emitted from the LEDs 42 may beaffected by ambient temperature. If associated with a thermistor S_(T)or other temperature-sensing device, the control circuitry 70 cancontrol the current provided to each of the LED strings S1, S2, and S3based on ambient temperature in an effort to compensate for adversetemperature effects. The intensity or color of the light emitted fromthe LEDs 42 may also change over time. If associated with an LED lightsensor S_(L), the control circuitry 70 can measure the color of theresultant white light being generated by the LED strings S1, S2, and S3and adjust the current provided to each of the LED strings S1, S2, andS3 to ensure that the resultant white light maintains a desired colortemperature or other desired metric. The control circuitry 70 may alsomonitor the output of the occupancy and ambient light sensors S_(O) andS_(A) for occupancy and ambient light information.

The control circuitry 70 may include a central processing unit (CPU) andsufficient memory 72 to enable the control circuitry 70 tobidirectionally communicate with the communications module 32 or otherdevices over the communication bus 38 through an appropriatecommunication interface (I/F) 74 using a defined protocol, such as thestandard protocol described above. The control circuitry 70 may receiveinstructions from the communications module 32 or other device and takeappropriate action to implement the received instructions. Theinstructions may range from controlling how the LEDs 42 of the LED array20 are driven to returning operational data, such as temperature,occupancy, light output, or ambient light information, that wascollected by the control circuitry 70 to the communications module 32 orother device via the communication bus 38. As described further below inassociation with FIG. 21, the functionality of the communications module32 may be integrated into the driver module 30, and vice versa.

With reference to FIG. 18, a block diagram of one embodiment of thecommunications module 32 is illustrated. The communications module 32includes a CPU 76 and associated memory 78 that contains to therequisite software instructions and data to facilitate operation asdescribed herein. The CPU 76 may be associated with a communicationinterface 80, which is to be coupled to the driver module 30, directlyor indirectly via the communication bus 38. The CPU 76 may also beassociated with a wired communication port 82, a wireless communicationport 84, or both, to facilitate wired or wireless communications withother lighting fixtures 10 and remote control entities.

The capabilities of the communications module 32 may vary greatly fromone embodiment to another. For example, the communications module 32 mayact as a simple bridge between the driver module 30 and the otherlighting fixtures 10 or remote control entities. In such an embodiment,the CPU 76 will primarily pass data and instructions received from theother lighting fixtures 10 or remote control entities to the drivermodule 30, and vice versa. The CPU 76 may translate the instructions asnecessary based on the protocols being used to facilitate communicationsbetween the driver module 30 and the communications module 32 as well asbetween the communications module 32 and the remote control entities. Inother embodiments, the CPU 76 plays an important role in coordinatingintelligence and sharing data among the lighting fixtures 10 as well asproviding significant, if not complete, control of the driver module 30.While the communications module 32 may be able to control the drivermodule 30 by itself, the CPU 76 may also be configured to receive dataand instructions from the other lighting fixtures 10 or remote controlentities and use this information to control the driver module 30. Thecommunication module 32 may also provide instructions to other lightingfixtures 10 and remote control entities based on the sensor data fromthe associated driver module 30 as well as the sensor data andinstructions received from the other lighting fixtures 10 and remotecontrol entities.

Power for the CPU 76, memory 78, the communication interface 80, and thewired and/or wireless communication ports 82 and 84 may be provided overthe power bus 40 via the power port. As noted above, the power bus 40may receive its power from the driver module 30, which generates the DCpower signal. As such, the communications module 32 may not need to beconnected to AC power or include rectifier and conversion circuitry. Thepower port and the communication port may be separate or may beintegrated with the standard communication interface. The power port andcommunication port are shown separately for clarity. The communicationbus 38 may take many forms. In one embodiment, the communication bus 38is a 2-wire serial bus, wherein the connector or cabling configurationmay be configured such that the communication bus 38 and the power bus40 are provided using four wires: data, clock, power, and ground.

In other embodiments, the communication bus 38 and the power bus 40 maybe effectively combined to provide a communication bus 38 p that notonly supports bidirectional communications, but also provides DC power,as shown in FIG. 19. In a 4-wire system, two wires may be used for dataand clock signals, and another two wires may be used for power andground. The availability of the communication bus 38 _(P) (orcommunication bus 38) allows auxiliary modules to be coupled to thecommunication bus 38 _(P). As shown in FIG. 19, the driver module 30, acommunications module 32, and an auxiliary sensor module 86 are allcoupled to the communication bus 38 _(P) and configured to use astandard protocol to facilitate communications therebetween. Theauxiliary sensor module 86 may be specially configured to senseoccupancy, ambient light, light output, temperature, or the like andprovide corresponding sensor data to the communications module 32 or thedriver module 30. The auxiliary sensor module 86 may be used to providedifferent types of supplemental control for the driver module 30 as wellas the communications module based on different lighting applications orrequirements.

While any number of functions or control techniques may be employed byan auxiliary sensor module 86, several examples are shown in FIG. 20.The illustrated auxiliary sensor modules include: an occupancy module 86_(O), an ambient light module 86 _(A), a temperature module 86 _(T), andan emergency module 86 _(E). The occupancy module 86 _(O) may beconfigured with an occupancy sensor and function to provide informationbearing on whether the room in which the lighting fixture 10 is mountedis occupied. When the room is initially occupied, the communicationsmodule 32 may instruct the driver module 30 to drive the LED array 20such that the lighting fixture 10 is effectively turned on and provideinstructions for other lighting fixtures 10 in the same zone to do thesame.

The ambient light module 86 _(A) may include an ambient light sensorthat is capable of measuring ambient light, determining thecharacteristics of the ambient light, and then providing suchinformation to the communications module 32 or the driver module 30. Asa result, either the communications module 32 will instruct the drivermodule 30 or the driver module 30 will independently function to drivethe LED array 20 in a manner based on the amount or characteristics ofthe ambient light. For example, if there is a lot of ambient light, thedriver module 30 may only drive the LED array 20 to a levelcorresponding to 20% of its maximum light output. If there is little orno ambient light, the driver module 30 may drive the LED array 20 at ornear maximum capacity. In more sophisticated embodiments, the ambientlight module 86 _(A), the driver module 30, or the communications module32 may analyze the quality of the ambient light and cause the drivermodule 30 to drive the LED array 20 in a manner based on the quality ofthe ambient light. For example, if there is a relatively large amount ofreddish light in the ambient light, the ambient light module 86 _(A) mayinstruct the driver module 30 to drive the LED array 20 such that theless efficient, red LEDs 42 _(R) are driven at a lower level than normalto improve the overall efficiency of the lighting fixture 10. Thecommunications module 32 may share the ambient light data with the otherlighting fixtures 10 or remote control entities as well as process theambient light data from one or more lighting fixtures 10 and provideinstructions to other lighting fixtures 10 based thereon.

The temperature module 86 _(T) may include a sensor capable ofdetermining the ambient temperature of the room, the LED array 20, orelectronics associated with any of the modules. The ambient temperaturedata may be used to cause the driver module 30 to drive the LED array 20in an appropriate fashion. The last illustrated auxiliary sensor moduleis an emergency module 86 _(E). The emergency module 86 _(E) illustratesan application type module, wherein the overall lighting fixture 10 maybe converted to operate as an emergency lighting fixture when associatedwith the emergency module 86 _(E). The emergency module 86 _(E) may beable to communicate with the driver module 30 and determine the state ofthe AC input signal (AC IN), the operational state of the driver module30, or the like, and then control the driver module 30 in an appropriatefashion or provide information bearing on the operational state to thecommunications module 32. For example, if there is a power failure inthe AC input signal (AC IN), the emergency module 86 _(E) may instructthe driver module 30 to switch over to a battery backup supply (notshown) and drive the LED array 20 at an appropriate level for anemergency lighting condition. The emergency module 86 _(E) may alsoretrieve various metrics for the AC input signal (AC IN), the drivermodule 30, or the LED array 20, and pass this information to thecommunications module 32. The communications module 32 may then pass theinformation or generate instructions for the other lighting fixtures 10or a remote control entity.

For the various modules that are coupled to the communication bus 38_(P), one embodiment assigns a unique ID to each of the modules, suchthat one or more of the other modules can uniquely identify them. Theidentifiers may also correspond to the functionality or type of module.As such, the driver module 30 may be able to identify the variousauxiliary sensor modules 86 and communications module 32 that reside onthe communication bus 38 _(P) and recognize the functionality providedby those modules. As such, the driver module 30 or communications module32 can prioritize commands received by the various modules and manageconflicts therebetween.

With reference to FIG. 21, an embodiment is provided wherein thefunctionality of the above-described driver module 30 and communicationsmodule 32 are integrated. In essence, the control circuitry 70 isexpanded to include the functionality of the communications module 32.As such, the control circuitry 70 may be associated with various wiredor wireless communication ports 82′ and 84′ to facilitate communicationswith the other lighting fixtures 10 and remote control entities, asdescribed above. Such an embodiment is generally less expensive tomanufacture, but may not provide as much flexibility as the aboveembodiments that employ distinct communications modules and drivermodules 30.

As shown in FIG. 22, a standalone sensor module 86′ may be provided inthe lighting system. The standalone sensor module 86′ may include one ormore sensors, such as an ambient light sensor S_(A) and an occupancysensor S_(O) as shown, and be proximately located with lighting fixtures10 that do not have these sensors. As such, the communications modules32 of the lighting fixtures 10 that do not have these sensors maycommunicate with the standalone sensor modules 86′ to obtain ambientlight, occupancy, or other available sensor data and then function asdescribed above. As such, some or all of the lighting fixtures 10 in azone or area of the lighting system need not have sensors or certaintypes of sensors. For example, some or all of the lighting fixtures 10in a room may have ambient lighting sensors S_(A); however, none of thelighting fixtures 10 may need an occupancy sensor S_(O), if one or morestandalone sensor modules 86′ are available with at least an occupancysensor S_(O) in the room.

The electronics of the standalone sensor module 86′ may appear similarto a communications module 32. For example, the communications module 32includes a CPU 76′ and associated memory 78′ that contains the requisitesoftware instructions and data to facilitate operation as describedherein. The CPU 76′ may also be associated with a wired communicationport 82, a wireless communication port 84, or both, to facilitate wiredor wireless communications with the other lighting fixtures 10 or remotecontrol entities. The standalone sensor modules 86′ may also beconfigured to provide control instructions, in addition to just sensordata, to the other lighting fixtures 10 of a lighting system. Varioustypes of control may be provided based on its own sensor data as well assensor data collected from other lighting fixtures 10 and standalonesensor modules 86′.

With reference to FIG. 23, an exemplary commissioning tool 36 isillustrated. The commissioning tool 36 may include a CPU 88, andsufficient memory 90 to facilitate the functionality described above.The CPU 88 may be associated with a keypad 94 and display 96, which actin combination to provide a user interface. The keypad may be atraditional alpha-numeric keypad and/or a series of buttons that havespecifically assigned functions. The display 96 may be a touchscreendisplay, wherein a separate hardware-based keypad 94 is not needed.Status indicators 98 may be used to provide the user feedback regardingthe status of a function, a certain activity, and the like. The CPU 88is associated with one or more communication interfaces, such as a wiredcommunication interface 100 and a wireless communication interface 102,which facilitates wired or wireless communications with any of thelighting fixtures 10, other control entities, standalone sensor modules86′, and the like. The LED driver 104 may also function as acommunication interface to allow the commissioning tool 36 tocommunicate with the lighting fixtures 10, sensors, and switches thatare equipped with an ambient light sensor S_(A) or other light receiver.The ambient light used for communications may reside in the visibleand/or non-visible light spectrum. For instance, the communications maybe infrared.

All of the electronics in the commissioning tool 36 may be powered froman appropriate power source 106, such as a battery. The commissioningtool 36 may be used to program the lighting fixtures 10, sensors, andswitches, as well as adjust any settings, load settings, receive sensordata, provide instructions, and the like. In essence, the commissioningtool 36 may act as a portable user interface for each of the lightingfixtures 10 and standalone sensors and switches as well as act as aremote control entity via which various data processing and control maybe provided. Typically, the commissioning tool 36 will be used toinitiate the setup of a lighting network, make adjustments to thenetwork, and receive information from the lighting network. Thecommissioning tool 36 is particularly useful when the lighting networkhas no other interface to facilitate connection to another remotecontrol entity.

Once the lighting fixtures 10 and any standalone sensors and switchesare installed, the commissioning tool 36 may initially be used to assignaddresses or IDs to the lighting fixtures 10 and standalone sensors andswitches, if addresses or IDs are not pre-programmed into the devices.The commissioning tool 36 may also be used to assign the variouslighting fixtures 10 and standalone sensors and switches into variousgroups, which will represent the lighting entities for a particularzone. The commissioning tool 36 may also be used to change groupassignments as well as remove a lighting fixture 10 or a standalonesensor or switch from a group or lighting system in general. Thecommissioning tool 36 may also be able to instruct a particular lightingfixture 10 or standalone sensor or switch to provide this functionalityfor a particular zone or for the overall lighting system. Exemplarycommissioning processes that employ the commissioning tool 36 areillustrated further below.

For access control, the commissioning tool 36 will be able to establishcommunications with a particular entity and authenticate itself. Oncethe commissioning tool 36 has authenticated itself with a lightingfixture 10 or a standalone sensor or switch in a particular group or inthe overall lighting system, the commissioning tool 36 may beauthenticated automatically with the other members of the group orlighting system. Further, various lighting fixtures 10 or standalonesensor or switch may be able to facilitate communications between otherlighting fixtures 10 and standalone sensor or switch and thecommissioning tool 36. Alternatively, the commissioning tool 36 may beconfigured only to communicate with a lighting fixture 10 or standalonesensor or switch when in close proximity. This may be accomplishedthrough a physical plug-in connection or through a low-power infrared orradio frequency communication link. Employing direct or short-rangecommunication techniques allows the commissioning tool 36 to be placedin close proximity to a particular lighting fixture 10 or standalonesensor or switch and only communicate with the entity or entities withinthe limited communication range.

The internal logic or programming of the standalone sensors or switchesmay be downloaded from, modified by, or replaced by the commissioningtool 36, or by any other remote control entity. As such, lightingdesigners and maintenance technicians are equipped to configure theoverall lighting network to function in a way that best achieves theirintended lighting goals. Accordingly, all or various groups of lightingfixtures 10 and standalone sensors or switches may be configured to actin synch with one another for certain applications and independentlyfrom one another in other applications. The commissioning tool 36 maytake various forms, such as a handheld device with a form factor similarto a smartphone or tablet. Various ports on the communication interface92 may be used to install external sensors, displays, keypads, and thelike, as well as facilitate an interface to a personal computer orcomputer network. The commissioning tool 36 may also be a device with anarchitecture as described above and connected with a portable computingdevice such as a notebook PC, tablet, or smart phone. The combinationcould perform the commissioning tool functionality

As indicated above, the various lighting fixtures 10, as well as thestandalone sensors or switches, share sensor data, instructions, andother information. In many instances, such information may need to berouted through one or more intermediate lighting fixtures 10 orstandalone sensor modules 86′ before reaching an intended destination.As such, these lighting fixtures 10 and standalone sensors or switchesmay function as routing nodes within the overall lighting system. Thefollowing describes unique and efficient techniques for assigningaddresses, configuring routing tables, and accessing these routingtables to facilitate the exchange of information among the variousentities of the lighting system. These techniques make lighting systemssuch as the one described above more reliable and predictable in termsof their requirements.

With reference to FIG. 24, an exemplary standalone switch module 110 isprovided. The switch module 110 may include a CPU 112 and sufficientmemory 114 to facilitate operation of the switch. Switch circuitry 116is capable of determining whether the switch should be on or off, aswell as a dimming position. Based on the on/off/dimming position, theswitch circuitry 116 will provide corresponding information to the CPU112, which is capable of processing the information and determiningwhether or not to send a command or corresponding status information toone or more nodes in the lighting network. The switch module 110 maycommunicate with other nodes in the lighting network through a wiredcommunication interface 120 or a wireless communication interface 122.For the wired communication interface 120, the type of connectivity mayrange from running signals over existing AC lines, a separate interfacecabling, which would perhaps support serial bus communications, or aproprietary interface. The wireless communication interface 122 mayfacilitate communications wirelessly with the network and effectively beanother node in the mesh network provided by the lighting network. Theswitch module 110 may also include an ambient light sensor S_(A) and anoccupancy sensor S_(O), which can provide ambient light conditionsand/or occupancy information to the CPU 112, which may process ambientlight conditions and/or occupancy information in order to control how toinstruct the other nodes in the lighting network to function, or merelypass the ambient light and/or occupancy information to a controllingnode in the lighting network. The switch module 110 may also include alight source 118, such as an LED, to provide status indication orfacilitate near field visible or non-visible light-based communicationswith the commissioning tool 36 or other device. The ambient light sensorS_(A) may also receive visible or non-visible light-based communicationsfrom the commissioning tool 36 or other device. Notably, the switchmodule 110 may include additional or less functionality relative to thatillustrated in FIG. 24.

Network Devices in Exemplary Lighting System

The following is a description of a particular system that employsexemplary wireless communication techniques of the present disclosure.The devices in the system may include switches, sensors, and lightingfixtures 10 of varying configurations. The system's communicationstopology may be an RF mesh network based on the IEEE 802.15.4 standard.As such, the various nodes on the network may communicate on one or morechannels in the 2.4 GHz band. The data rate in this configuration isnominally 200 kbps but actual throughput depends heavily on messagingoverhead and traffic volume.

Once the network is formed, most communications occur within groups,where groups include devices, such as the switches, sensors, andlighting fixtures, operating in tandem. With this particular system'semphasis on grouping, RF traffic should be relatively minimal once thesystem is up and running. Consequently for most applications, the RFmesh network will provide a perceptually instantaneous response, suchthat delays are not noticeable to the user. In practice, this means thatlighting fixtures 10 may typically respond within 100 msec to switch,sensor, or other control operations within their group.

The following describes the particular components and configurations ofthe switches, sensors, and lighting fixtures 10 of the illustratedsystem. As illustrated in FIG. 25, a smart fixture 130 is a componentthat includes a driver module 30, which is integrally associated with anLED array 20, ambient light sensor S_(A), and occupancy sensor S_(O).Communications with other modular components, as described below, arefacilitated via an I²C serial bus or the like, as noted above. In thisconfiguration, the driver module 30 is capable of providing DC power tomodules or components connected thereto.

As illustrated in FIGS. 26 and 27, an indoor RF communication moduleiRFM 32′ and outdoor RF communication module 32″ oRFM are variants ofthe communication module 32. The iRFM 32′ and the oRFM 32″ may connectto and provide wireless connectivity to the mesh network for variouslighting components, such as the smart fixture 130. The iRFM 32′ and theoRFM 32″ may receive power from and communicate with a coupled smartfixture 130 or other component via a standard connector. The iRFM 32′and oRFM 32″ support wireless connectivity to other devices that havewireless communication capabilities. FIG. 28 illustrates an iRFM 32′directly coupled to a smart fixture 130 to create a variant of alighting fixture 10. DC power is provided to the iRFM 32′ by the smartfixture 130. The iRFM 32′ and the smart fixture 130 communicate witheach other via the I²C serial bus.

As illustrated in FIG. 29, a fixture sensor module (FSM) 132 may beconnected to the iRFM 32′ and smart fixture 130 of FIG. 28 to addadditional sensing capabilities to the lighting fixture 10. The FSM 132is a type of auxiliary module 86 (FIG. 20) and is configured to obtainpower from the smart fixture 130 and provide pass-through connectors forplugging in the iRFM 32′ and the smart fixture 130. When the ambientlight sensor S_(A), occupancy sensor S_(O), or other sensor typegenerates an output change, the FSM 132 communicates the changes via thelocal I²C bus to both the attached smart fixture 130, and if present,the iRFM 32′. If an iRFM 32′ is connected, it wirelessly communicatesthe FSM sensor updates to an associated group of lighting devices in thesystem.

As illustrated in FIG. 30, an indoor or outdoor wireless sensor module134, which is either AC or battery-powered, may also be provided. Thewireless sensor 134 has a wireless communications interface and isconfigured to monitor ambient light conditions, room occupancy, or thelike using one or more ambient light or occupancy sensors S_(A), S_(O).To maximize battery life, the wireless sensor's communication andprocessing circuitry may remain turned off over 99% of the time. Whenoutputs from the sensors change, the communication and processingcircuitry turns on and sends a sensor update to lighting devices in anassociated group. The wireless sensor 134 is intended to be locatedphysically apart from other lighting fixtures 10, smart fixtures 130,and the like. Wireless sensors 134 may be placed in locations wheresensors, but not necessarily lighting elements, are needed or desired.

As illustrated in FIG. 31, a wireless relay module 136 may be used toallow wireless control of legacy (light) fixtures 138 to provide on/offcontrol and dimming thereof. When wireless communication circuitryreceives a wireless control signal, a relay may control AC powersupplied to the legacy fixture 138 and/or a control signal (0-10V) maybe provided to control a dimming level. The wireless relay module 136may also include ambient light and occupancy sensors S_(A), S_(O), andreport output changes wirelessly to other devices in the associatedgroup.

As illustrated in FIG. 32, a version of the switch module 110 configuredas a wireless on/off/dimming switch (WS) 140 is provided. The WS 140resides on the wireless communications network, and as described above,may include an ambient light sensor S_(A), on/off control, and dimmingcircuitry. When ambient light sensor S_(A) activates, the WS 140 sendsan update to the devices in its group. The RF design supports low poweroperation for battery power, but may be hardwired to an AC power source.

Exemplary Network Commissioning Procedure

Commissioning generally includes the steps of 1) forming the network, 2)collecting data for grouping network devices into groups, 3) running thegrouping process, 4) assigning groups for each device, and 5) revisinggroup assignments.

In this example, the handheld commissioning tool 36 is used to initiateand control the commissioning process. For an uninitialized system, auser asserts a ‘Start Commissioning’ process from the commissioning tool36 to begin network formation. This may simply entail moving thecommissioning tool 36 near a routing node, such as a lighting fixture10, and then initiating a one-button command on the commissioning tool36, which sends a ‘start network formation’ message. A routing node maybe any device on the network, such as a lighting fixture 10, that iscapable of acting as the coordinator and is able to route informationfrom one node to another.

For a routing node to become the coordinator, it may monitor a receivedsignal strength indicator (RSSI) associated with a message or the like,and determine that the RSSI is above a defined threshold. Other routingnodes may receive the message, but the RSSI will be below the definedthreshold. Sleeper nodes, such as battery-powered wireless sensors 134,wireless switches 140, and the like, will either be asleep or ignore thestart network formation message.

In this embodiment, assume the proximate routing node accepts the startnetwork formation message and asserts itself as the coordinator. Thecoordinator broadcasts a Join My Network (JMN) message to the othernon-coordinator routing nodes and subsequently allows thenon-coordinator nodes in the system to join the network. The coordinatorpermits joining and may assign “short” network addresses, which may be24, 16, 8 or so bits, to those non-coordinator routing nodes that joinedthe network. The short addresses are “short” in that they are shorterthan the corresponding MAC addresses for the devices, and will be usedinstead of the MAC addresses to facilitate communications throughout thenetwork once they are assigned. In this first stage of networkformation, the coordinator effectively establishes a network thatincludes all of the routing nodes.

In particular, the coordinator is tasked with sending a JMN message onmultiple, if not all, available communication channels. In that JMNmessage, the coordinator may indicate a selected channel on which thenon-coordinator routing nodes should respond. During the joiningprocess, the coordinator will provide short addresses to thosenon-coordinator routing nodes that are joining the network. Thecoordinator will also have a default short address, or will assignitself a short address. As noted, these short addresses will be used forcommunications during normal network operation. The coordinator willalso build its own routing tables to use when routing information fromone routing node to another.

In a cooperative fashion, the non-coordinator routing nodes willinitially listen for the JMN message. When the broadcasted JMN messageis received, the non-coordinator routing nodes will respond on theselected channel identified by the coordinator. The routing nodes willalso receive the short addresses assigned by the coordinator, store theshort addresses, and build their own routing tables. The unique MACaddresses for the various routing nodes may also be exchanged duringthis process. The coordinator will keep track of the nodes that haveresponded and may inform each node of the other nodes that make up thenetwork and the respective short addresses to effectively form therouting core of the network.

After allowing sufficient time for all routing nodes to join, thecoordinator will initiate and control the above described lightcastingprocess to help group the various routing nodes into different groups.As such, the coordinator will enter itself and then sequentially requesteach routing node to enter a lightcast mode. An exemplary lightcastwould entail providing a light output at 50% duty cycle at a pre-definedPWM frequency. As an alternative to the PWM frequency for the lightcastsignal, an on-off sequencing could be used.

While lightcasting, a routing node is considered a ‘lightcaster’ andwill transmit to routing nodes a stream of RF messages identifyingitself and indicating it is the current lightcaster. The other routingnodes act as lightcast receivers (or lightcatchers) by monitoring thelightcast signal from the given lightcaster, calculating the magnitudeof the lightcast signal, and storing the magnitudes of the lightcastsignal for the given lightcaster. Sleeper nodes, such as battery-poweredwireless sensors 134, wireless switches 140, and the like, may receivethe lightcast signal and turn on their radio receivers to hear the RFmessage indicating the identity of the lightcaster. During thelightcasting process, sleeper nodes may be triggered to wake up andrequest to join the network. The coordinator node will assign them shortaddresses while approving their join requests. After lightcasting wrapsup for all devices, the coordinator will send a message to thecommissioning tool 36 that network formation is complete.

Accordingly, the coordinator will sequentially send lightcast requestmessages to the routing nodes, accept join requests from sleeper nodes,and assign short addresses to those joining sleeper nodes. Thecoordinator will also save lightcast reception data, which is gatheredwhen the other lightcasters are lightcasting. The coordinator will alsoretain the lightcast reception data until requested by the commissioningtool 36 or other device. The non-coordinator lighting nodes will performlightcasting when requested as well as gather and save lightcastreception data during lightcasting from other lightcasters. Again, thelightcast reception data is stored until requested by the commissioningtool 36 or other device. For the sleeper nodes, which are normallyasleep, they will fully power on and submit Join Network’ (JN) requestmessages upon sensing the presence of a lightcast signal. The sleepernodes will receive short addresses from the commissioning tool 36 aswell as gather and save lightcast reception data. The lightcastreception data is saved until requested by the commissioning tool 36 oranother device. In other embodiments, the lightcast reception data maybe sent to a designated node, such as the coordinator, or to thecommissioning tool 36, as it is gathered.

Assuming that the lightcast reception data is stored until requested,the following process may be employed. To collect the lightcastreception data, the commissioning tool 36 queries each node for itslightcast reception data. Since a wireless mesh network is alreadyformed, the commissioning tool 36 may communicate with any routing nodeto establish the entry point to the network. Each node responds with itslightcast data.

In particular, the commissioning tool 36 may send out a request for thelightcast reception data. Both the coordinator and the non-coordinatorrouting nodes will respond with the lightcast reception data. In certainembodiments, the sleeper nodes may share their lightcast reception datawith a non-sleeper node, such as the non-coordinator routing nodes andthe coordinator. If this is the case, the lightcast reception data forthe sleeper nodes may be provided to the commissioning tool 36. If thesleeper nodes did not share their lightcast reception data with anon-sleeper node, the sleeper nodes may respond with their own lightcastreception data, if they are awake or when they are ultimately awakenedautomatically or through a lightcast or light signal.

After collecting the lightcast reception data, the commissioning tool 36proceeds with a grouping process. The commissioning tool 36 itself, orpossibly an attached notebook computer, executes a grouping algorithmfor determining optimal node grouping based on the lightcast receptiondata. Once the commissioning tool 36 (or attached PC) runs the groupingalgorithm, it communicates the group assignments and a group address toeach routing node in the network, wherein the group assignment data(inducing the group address) is sent to each routing node and includesall nodes within that routing node's group.

All sleeping nodes are grouped with at least one routing node. Sleepingnodes may receive their group assignment by either of two methods.First, each sleeping node wakes up periodically to send out its sensordata and to request system status updates from the network. In responseto the sleeper node's message, the associated routing node may respondand provide the sleeper node with its group assignment via the groupassignment data. The second method for assigning the group address tothe sleeper nodes requires that a routing node with sleeper nodes in itsgroup perform lightcasting to awaken the sleeper nodes. An awakenedsleeper node subsequently sends out its sensor data and requests systemstatus updates from the network. In response to the sleeper node'smessage, the associated routing node responds and provides the sleepernode its group assignment data.

Inevitably some group assignments will need to be modified. Thecommissioning tool 36 provides a way for checking and changing groupassignments. The commissioning tool 36 may include an LED (or othervisible or non-visible light) output that the user may point at anambient light sensor S_(A), which is embedded in a lighting fixture 10,wireless sensor 134, wireless relay module 136, wireless switch 140, orthe like that needs to be assigned to a different group. Thecommissioning tool 36 may use the LED to provide a lightcast signal aswell as send and receive RF messages to effect a group assignmentchange.

An exemplary process for reassigning a node, such as a smart fixture130, from one group to another follows. Initially, a user will point thecommissioning tool 36 at the smart fixture 130 to be reassigned andprovide a user input that is associated with reassigning a node from onegroup to another. The commissioning tool 36 will initiate acorresponding lightcast signal via its LED output, as well as send an RFmessage to request the short address of the smart fixture 130. The smartfixture 130 will receive the lightcast signal and listen for the RFmessage. The smart fixture 130 will provide an RF acknowledgementmessage, which includes the short address and the group address for thesmart fixture 130.

Next, the user will point the commissioning tool 36 at a node in the newgroup to which the smart fixture 130 is being moved. The user will pressa button or provide an input instructing the commissioning tool 36 tomove the smart fixture 130 to the new group. In response, thecommissioning tool 36 will initiate a lightcast signal as well as send acorresponding RF message indicating that a node is being moved to thenew group. The RF message will include the short address of the smartfixture 130. The node in the new group that is receiving the lightcastsignal will also receive the RF message from the commissioning tool 36.

Upon receipt, the node in the new group will send an acknowledgement tothe commissioning tool 36 as well as send a message to the smart fixture130 using the appropriate short address to provide the address for thenew group. The smart fixture 130 will update its group address and senda message to the commissioning tool 36 indicating that the move has beencompleted. Information associated with the other nodes in the new groupmay also be provided to the smart fixture 130 via the mesh network.After receiving the new group address from the node in the new group,the smart fixture 130 may also send an acknowledgement back to thecommissioning tool 36 as well as send a message to one or more nodes inthe old group indicating that it is changing groups. At this point, thesmart fixture 130 may monitor any sensor levels and provide anyavailable sensor data to the nodes in the new group via the meshnetwork. While the example reassigned a smart fixture 130 from one groupto another, this technique applies to any type of node in the network.

If the network requires re-initialization, the user may employ thecommissioning tool 36 to instruct the network nodes to revert to theirpre-commissioned settings. Presumably, starting this process willrequire a multi-step sequence to prevent inadvertent undo commands. Oncecommissioning is completed, and grouping corrections are made, thesystem is ready to operate. In general, switches and sensors provideinputs to the system. Lighting fixtures 10 interpret these inputs withinthe framework of their energy-saving settings and function accordingly.

Operation of the different types of devices in the network is describedbelow. A wireless relay module 136 (FIG. 31) monitors input data fromits group. This includes data from other switches, remote sensors, andits own internal sensors. Data from switches and remote sensors arrivesvia wireless network communications. Data from internal sensors isgathered and stored internally. The wireless relay module 136independently executes internal logic that interprets the various inputsand settings, and correspondingly outputs the 0-10V dimming control andrelay on/off control. The wireless relay module 136 relies on itswireless communication circuitry to perform message routing within themesh network. Routing occurs as a background activity and has no impacton the light-control operation.

The wireless relay module 136 may hold a message for a sleeping sleepernode in its group. When the node next awakens and requests an update,the wireless relay module 136 sends the held message to the awakenedsleeper node. Notably, the wireless relay module 136 processes itsinternal ambient light sensor data looking for a lightcast signal. Withthe network in normal operating mode, the only expected lightcast signalwill be from the commissioning tool 36. When the wireless relay module136 receives a commissioning tool's lightcast signal, it will performthe requested wireless command.

In most respects, a smart fixture 130 operates similarly to the wirelessrelay module 136. One major difference is that smart fixtures 130 aregenerally coupled with a communication module 32 to form a lightingfixture. The two modules may communicate with each other via the I²Cbus. Either of the modules may be used to process and store the sensordata; however, communications are provided by the communications module32.

Wireless sensors 134 provide ambient light and occupancy sensor data totheir groups. The wireless switches 140 provide on/off and dimminginformation via RF messages. The wireless sensors 134 periodically wakeup, monitor the sensors, and send sensor update messages to their group.The wireless switches 140 provide RF messages to indicate on, off, anddimming state changes. This allows group members to monitor the wirelesssensors 134 and wireless switches 140 within the group, process theinformation provided in the messages, and react accordingly. If routingnodes within the group have messages for the wireless sensors 134, theycommunicate these messages during the waking interval.

Automatic Coordinator Selection and Grouping Initiation

The preceding example relied on the commissioning tool 36 to initiatenetwork formation by selecting a routing node, such as a lightingfixture 10, to act as the coordinator. The coordinator will then assignshort addresses to the various network elements and assist thecommissioning tool 36 in making group assignments through thelightcasting process. For the next embodiment, a variant is describedwherein routing nodes automatically discover each other and worktogether to identify a coordinator, without external aid from thecommissioning tool 36 or other entity. The coordinator willautomatically assign short addresses for use with normal communicationswithin the network as well as automatically initiate and control thegrouping process using the previously described lightcasting.

Identification of the coordinator in this embodiment is an iterativeprocess wherein the various routing nodes will essentially exchangetheir typically 64-bit MAC addresses and decide that the routing nodewith the lower (or higher) MAC address should be the coordinator, atleast for the time being. The routing node with the lower MAC address(coordinator) will assign the routing node with the higher MAC address aunique short address. The coordinator and the other routing nodes willperiodically send out requests, such as the JMN requests, to join theirnetworks. If a first routing node that has been assigned as coordinatorexchanges MAC addresses with a second routing node that has a lower MACaddress, the first routing node will relinquish its coordinator role tothe second routing node having the lower MAC address. The second routingnode will promptly assign a short address to the first routing node.After a few iterations, the routing node with the lowest (or highest)MAC address in the network will be set as the coordinator and will haveassigned short addresses for to each routing node in the network. Again,the coordinator assignment process could just as easily find the routingnode with the highest MAC address as opposed to the one with the lowestMAC address. Also, other unique identifying criteria may be exchanged toidentify the coordinator in an analogous process. Further, shortaddresses are optional, and are used merely to speed up the routingprocess during normal operation. Alternative embodiments may forego theuse of short addresses and rely on the MAC or other addresses forrouting, as done in traditional mesh networks.

Sleeper or other non-routing nodes will wake up periodically and obtaintheir short addresses from the coordinator directly or from thecoordinator via an associated routing node. All other functions, such asoverall control, exchanging switch and sensor information, setting uprouting tables, routing messages through the network, lightcastingcontrol, grouping, and the like can be handled as described above.Further, a commissioning tool 36 may still be used to tweak settings,regroup elements, and the like as described above.

A few exemplary communication flows are described below to illustratevarious scenarios for selecting a coordinator for a network. In theseflows, four different routing nodes A through D are described. In thevarious flows, 64-bit MAC addresses are provided for these nodes. Forsimplicity's sake, the MAC addresses used are: EEEE EEEE EEEE EEEE (thehighest MAC address in the examples); AAAA AAAA AAAA AAAA; 8888 88888888 8888; and 1111 1111 1111 1111 (the lowest MAC address in theexamples). For conciseness and readability, these MAC addresses arereferenced below and in the associated communication flows as [E-E],[A-A], [8-8], and [1-1], respectively.

With reference to the communication flow of FIG. 33, assume routing nodeA has a MAC address of [A-A], and routing node B has a MAC address of[E-E]. As such, routing node B has a higher MAC address than routingnode A. In this example and in the examples following this one, assumethat the coordinator role should be assigned to the routing node withthe lowest MAC address. Initially, routing node A is set to its defaultsettings and is programmed to periodically broadcast a JMN (Join MyNetwork) message to request other routing nodes to join routing node A'snetwork, which at this point is a one-element network. As such, routingnode A's initial network will only include routing node A. In essence,routing node A may default to thinking that it is a coordinator.

With continued reference to FIG. 33, assume that routing node Abroadcasts a JMN message, including its MAC address (MAC-A) (step 600).Routing node B will be listening for JMN messages, and will respond torouting node A's JMN message by storing the MAC address (MAC-A) forrouting node A (step 602) and then comparing routing node A's MACaddress (MAC-A) with its own MAC address (MAC-B) (step 604). Routingnode B will recognize that routing node A's MAC address [A-A] is lessthan routing node B's MAC address [E-E] and will set the coordinator forits associated network to routing node A's MAC address (step 606). Atthis point, routing node B assumes that routing node A, which isassociated with the MAC address [A-A], is the coordinator of the networkto which it belongs.

In response to the JMN message, routing node B will also send a JMNresponse with its MAC address (MAC-B) back to routing node A (step 608).Routing node A will compare its MAC address (MAC-A) with that of routingnode B (MAC-B) (step 610) and will recognize that it has the lower MACaddress, and thus should remain the coordinator of the network.Accordingly, routing node A will generate a short address (B_(A)) forrouting node B's MAC address (MAC-B) (step 612) and will send the shortaddress to routing node B (step 614). Routing node B will then save theshort address (B_(A)), which was assigned by routing node A (step 616),and if not subsequently changed by another routing node that becomes thecoordinator, will use the short address for communications and routingwithin the network.

In the above example, the routing node (A) with the lower MAC addressoriginated the JMN message, and the routing node (B) with the higher MACaddress joined the JMN message originator's network. In the nextexample, illustrated in FIG. 34, the routing node (B) receiving the JMNmessage becomes the coordinator because it has a lower MAC address. Inthis example and with reference to FIG. 34, routing node A is associatedwith a higher MAC address [A-A] than routing node B, which has a lowerMAC address [8-8]. At some point, assume that routing node A broadcastsa JMN message, which includes routing node A's MAC address (MAC-A) (step700). The broadcast message is received by routing node B, whichproceeds to store the MAC address (MAC-A) for routing node A (step 702)and then compares routing node A's MAC address (MAC-A) with routing nodeB's MAC address (MAC-B) (step 704). In contrast with the exampleillustrated in FIG. 33, routing node B will recognize that it should setitself as the coordinator, since its MAC address (MAC-B) is less thanrouting node A's MAC address (MAC-A) (step 706). Since routing node B isthe coordinator, it will generate a short address (A_(B)) associatedwith routing node A's MAC address (MAC-A) (step 708). Next, routing nodeB will send a JMN response message, which includes routing nodes B's MACaddress (MAC-B) to routing node A (step 710) and immediately follow witha message providing the short address (A_(B)) to routing node A (step712). Routing node A will then recognize that it is no longer thecoordinator, and will set the coordinator to routing node B's MACaddress (MAC-B) (step 714), which effectively recognizes routing node Bas the coordinator for the network to which routing node A belongs.Routing node A will also save the short address (A_(B)) as the shortaddress that routing node A will use for communications over the network(step 716).

Turning now to the communication flow illustrated in FIGS. 35A-35C, amore complex scenario is illustrated wherein multiple routing nodes (Band C) receive an initial JMN message from routing node A. The examplealso shows a fourth routing node (D) that does not initially receive theJMN message of routing node A, but ultimately joins the network,recognizes the network's coordinator, and receives a short address fromthe coordinator. This example shows the coordinator being transitionedfrom routing node A to routing node B and then to routing node C. Assumethat the MAC addresses for routing nodes A, B, C, and D are as follows:

-   -   MAC-A [A-A];    -   MAC-B [8-8];    -   MAC-C [1-1]; and    -   MAC-D [E-E].

Thus, routing node C has the lowest MAC address and routing node D hasthe highest MAC address.

Initially, assume that routing node A broadcasts a JMN message with itsMAC address (MAC-A) (step 800). Assume that routing node B and routingnode C receive the JMN message, and that routing node D does not receivethe JMN message. Further assume that routing node B is the fasterrouting node to respond to the JMN message. As such, routing node B willprocess the JMN message by storing routing node A's MAC address (MAC-A)(step 802) and comparing routing node A's MAC address (MAC-A) with itsown MAC address (MAC-B) (step 804). As with the previous example,routing node B will set itself as the coordinator since routing node B'sMAC address (MAC-B) is less than routing node A's MAC address (MAC-A)(step 806). Routing node B will generate a short address (A_(B)) forrouting node A's MAC address (MAC-A) (step 808) and send an appropriateJMN response including routing node B's MAC address (MAC-B) to routingnode A (step 810). Routing node B will also send the short address forrouting node A (A_(B)) to routing node A in a separate message (step812). Although separate messages are used for the JMN response andproviding the short address, those skilled in the art will recognizethat this information may be provided in a single message. Again,routing node A, having the higher MAC address, will set the coordinatorto routing node B's MAC address (MAC-B), indicating that routing node Bwill become the coordinator, at least for the time being (step 814).Routing node A will also store the short address (A_(B)) assigned byrouting node B (step 816).

Substantially concurrently, routing node C will also process the JMNmessage that was provided by routing node A (in step 800). In response,routing node C will store routing node A's MAC address (MAC-A) (step818) and compare routing node A's MAC address (MAC-A) with routing nodeC's MAC address (MAC-C) (step 820). Routing node C will also recognizethat its MAC address (MAC-C) is lower than routing node A's MAC address(MAC-A) and set itself as the coordinator (step 822). As thecoordinator, routing node C will generate a short address (A_(C)) forrouting node A's MAC address (step 824). Routing node C will then send aJMN response message including its MAC address (MAC-C) (step 826) andanother message providing the short address (A_(C)) for routing node A(step 828) to routing node A. Routing node A will recognize that routingnode C thinks it should be the coordinator, and will reset theidentified coordinator to routing node C's MAC address (MAC-C), sincerouting node C's MAC address is less than routing node B's MAC address(step 830). Routing node A will also update its short address with theshort address (A_(C)), assigned by routing node C (step 832). As such,routing node B has been uprooted as the coordinator from the perspectiveof routing node A. In certain examples, if routing node B would have hadthe lower MAC address, routing node A would have maintained that routingnode B was the coordinator and would have ignored the messages fromrouting node C. This portion of the example highlights the fact thatmultiple routing nodes may think they are the coordinator during thisiterative coordinator identification process.

At this time, routing node B may continue to think that it is thecoordinator, and will periodically broadcast JMN messages to otherrouting nodes. In this instance, routing node B broadcasts a JMN messageincluding routing node B's MAC address (MAC-B) that is received by bothrouting node A and routing node C (step 834). Routing node A willeffectively ignore the JMN message sent by routing node B, because itrecognizes that the currently assigned coordinator, routing node C, hasa MAC address less than that of routing node B (step 836). However,routing node C will respond differently, because routing node C has alower MAC address (MAC-C) than routing node B. As such, routing node Cwill store routing node B's MAC address (MAC-B) (step 838) and comparerouting node B's MAC address (MAC-B) with routing node C's MAC address(MAC-C) (step 840). Routing node C will then recognize that it shouldremain the coordinator, because it has a lower MAC address (step 842)and then generate a short address (B_(C)) for routing node B's MACaddress (MAC-B) (step 844). Routing node C will then send a JMN responseincluding its MAC address (MAC-C) (step 846) and a short address messageincluding the short address (B_(C)) for routing node C (step 848) torouting node B. In response, routing node B will reset the coordinatorto routing node C using routing node C's MAC address (MAC-C) (step 850)and store B_(C) as its short address (step 852).

During this time, assume that routing node D becomes available (step854), and as coordinator, routing node C begins periodicallybroadcasting JMN messages. As such, routing node C will send a JMNmessage including its MAC address (MAC-C), which is received by routingnode A, routing node B, and routing node D (step 856). Routing nodes Aand B will effectively ignore the JMN messages, because they recognizethat these messages are sent by the recognized coordinator, routing nodeC (steps 858 and 860). Since routing node D is a new party withincommunication range of the network, routing node D will process the JMNmessage. Accordingly, routing node D will store routing node C's MACaddress (MAC-C) (step 862) and compare routing node C's MAC address(MAC-C) with routing node D's MAC address (MAC-D) (step 864). Sincerouting node D will recognize that it has a higher MAC address thanrouting node C, routing node D will recognize that routing node C shouldbe the coordinator and will set the coordinator to routing node C's MACaddress (MAC-C) (step 866). As such, routing node D will not assign ashort address for routing node C, since routing node C is thecoordinator. Routing node D will simply respond to the JMN message byproviding a JMN response message, which includes routing node D's MACaddress (MAC-D) to routing node C (step 868). Routing node C willcompare its MAC address (MAC-C) with routing node D's MAC address(MAC-D) (step 870). Since routing node C has the lower MAC address andshould remain the coordinator, routing node C will generate a shortaddress (D_(C)) for routing node D's MAC address (MAC-D) (step 872) andwill send a message including the short address (D_(C)) for routing nodeD to routing node D (step 874). Routing node D will store the shortaddress (D_(C)) for use with subsequent communications (step 876).

At some point during the process, if routing node C does not have adefault short address that is known to the other routing nodes, it willassign itself a short address (step 878). Routing node C may assignitself a short address and provide the short address to the otherrouting nodes in any desired fashion. The benefit of having a defaultshort address for the coordinator is that all other routing nodes,whether they have been assigned a short address or not, may use a shortaddress to route messages through the network to the coordinator usingtraditional mesh network routing techniques.

At this point, the coordinating routing node C can join non-routing(sleeper) nodes to the network and assign them short addresses (step880) as well as initiate the aforementioned grouping process (step 882)and carry out various control, routing, and the like using the assignedshort addresses (step 884). Nodes that are subsequently added to thenetwork may have lower MAC addresses than that of routing node C, and inthose situations, the newly added routing node with the lower MACaddress may take over as coordinator and reassign short addresses to allthe routing and non-routing nodes in the network. Further, thecommissioning tool 36 may interact with the automatically identifiedcoordinator to modify grouping assignments and the like. The coordinatormay also be changed or reassigned by the commissioning tool 36 asdesired by the network administrator.

Multiple Master Lighting Fixture Configuration

With reference to FIG. 36, an exemplary lighting fixture 10 isillustrated as having a driver module 30 with an associated LED array20, a communication module 32, a fixture sensor module 132, and agateway 142. The driver module 30, communication module 32, fixturesensor module 132, and the gateway 142 may be configured to communicatewith each other over a 2 or more wire serial interface, such as the I²Cbus, to allow each of the devices to exchange information, such as dataand control information, as desired. As described above, thecommunication module 32 may facilitate wireless communications withother nodes in the wireless network, and essentially act as acommunication interface for the lighting fixture 10 in general, and inparticular for the gateway 142, the driver module 30, and the fixturesensor module 132. The gateway 142 may facilitate wirelesscommunications with entities outside of the network, such as a remotecontroller or to a remote network, perhaps using a different wirelesscommunication interface. For example, the communication module 32 mayfacilitate wireless communications with other nodes in the lightingnetwork using the IEEE 802.15.4 standard on one or more channels in the2.4 GHz band, whereas the gateway 142 may facilitate communications in adifferent band, using a different communication standard, such ascellular or other IEEE standard, or the like. Accordingly, one of thelighting fixtures 10 may be provided with the gateway 142, which willact as an access point or node for the entire lighting network. Thegateway 142 is shown with a CPU 144, a wireless communication interface146, and a serial communication interface 148. The wirelesscommunication interface 146 supports wireless communications withexternal networks or devices, whereas the serial communication interface148 facilitates communications over the 2-wire serial interface.

Also shown is an exemplary (on/off/dim) switch 140′, which has anambient light sensor S_(A), and in this embodiment, a cable that iscapable of interfacing with the 2-wire serial interface of the lightingfixture 10. As such, the switch 140′ may be located remotely from thelighting fixture 10, and yet be integrated via the 2-wire serialinterface. On, off, and dimming control may be provided to thecommunication module 32 or the driver module 30 via the 2-wire serialinterface, where either of the communication module 32 or the drivermodule 30 will process these commands internally as well as provide thecommands to other nodes, such as other lighting fixtures, that residewithin the same group as the lighting fixture 10. The fixture sensormodule 132 may have both ambient light and occupancy sensors S_(A) andS_(O), wherein ambient light and occupancy measurements may be sharedwith either the communication module 32 or the driver module 30, eitherof which may process the commands and react accordingly internally aswell as share the information with other members of the group. Again,the driver module 30 may also include various sensors, such as theambient light sensor S_(A) that is illustrated.

Overall control for the lighting fixture 10 may be provided by thecommunication module 32, wherein all internal and directly attachedcontrol information is sent to the communication module 32, which willprocess the information according to its internal logic and control theassociated driver module 30 accordingly, as well as send controlinformation to other nodes in its group or to the network in itsentirety. Conversely, the driver module 30 may provide thisfunctionality, wherein sensor and switch information is provided to thedriver module 30 and processed by its internal logic to control the LEDarray 20. The driver module 30 may also share this control informationor the data and sensor information with other members of the network viathe communication module 32. A further modification of this scenariowould be wherein the on/off/dim switch 140′ is capable of wirelesslycommunicating with the communication module 32 to share its sensorinput, as well as send information to other devices on the network.

As noted, various serial interface technologies may be employed. In thefollowing example, an I²C interface is employed in an uncharacteristicfashion. In this embodiment, primary control of the lighting fixture 10is provided in the driver module 30. If an I²C interface is used, thedriver module 30 is configured as a slave device, whereas the otherentities that are communicating over the I²C interface, including thecommunication module 32, fixture sensor module 132, gateway 142, and theon/off/dim switch 140′, are all configured as master devices. Thisconfiguration is counterintuitive to previous implementations of an I²Cbased bus structure. With the driver module 30 acting as a slave device,the other master devices can initiate transfers, and thus send orrequest data to or from the driver module 30, at any time without havingto wait or alert the driver module 30 in advance of initiating thetransfer. As such, the driver module 30 does not have to periodically orconstantly poll the other devices that are attached to the I²C interfacein search of switch, sensor, or communication changes. Instead, themaster devices are configured to automatically initiate switch, sensor,or communication changes to the driver module 30, wherein the drivermodule 30 is configured to readily receive this information and processit accordingly. The master devices may also request information from thedriver module 30, which may have the information on hand and provide itback to the requesting master device, or may retrieve the informationfrom another network node via the communication module 32, or anotherdevice within or associated with the lighting fixture 10.

As an example, if the ambient light sensor S_(A) or the occupancy sensorS_(O) of the fixture sensor module 132 detects a change, the fixturesensor module 132 is configured to initiate a transfer of informationrepresentative of the sensor change or changes to the driver module 30.The driver module 30 will process the information and determine whetheror not the LED array 20 needs to be turned on or off or varied in lightoutput based on its own internal logic. The driver module 30 may alsogenerate a control command or message that includes the sensorinformation that is sent to other nodes in its associated group or thenetwork in general via the communication module 32. For a controlcommand, the receiving device may respond as directed. For the sensorinformation, the receiving device may process the sensor information anddetermine how to control itself based thereon. Similar operation isprovided by the on/off/dim switch 140′, wherein an on/off or dimmingadjustment is detected, and the on/off/dim switch 140′ will initiate atransfer of the switch status or status change to the driver module 30,which will again process the information to control the LED array 20 asneeded and provide any necessary instructions to other nodes on thenetwork via the communication module 32.

Commands or shared data, such as sensor information, may also arrive atthe lighting fixture 10 via the communication module 32. As such, thecommunication module 32 will receive a command or the shared data fromanother node in the associated group or the network in general, andinitiate a transfer to the driver module 30, which will process thecommand or interpret the shared data based on its own internal logic andcontrol the light array 20 in an appropriate fashion. In addition tosimply providing status information, data, and commands to the drivermodule 30, any of these devices may request information that the drivermodule 30 maintains. For example, in a lightcasting process, thecommunication module 32 may receive a request for the lightcast datafrom the commissioning tool 36. The communication module 32 willinitiate a request for the information to the driver module 30, whichwill provide the information back to the communication module 32. Thecommunication module 32 will then route the information back to thecommissioning tool 36, directly or indirectly through other routingnodes in the network.

While the illustrated master-slave configuration is very beneficial, itis not necessary to practice the concepts disclosed herein. A benefit ofthis type of configuration is that the other devices within the lightingfixture 10 need not be aware of the others' existence, if their data andstatus information is collected and maintained on the driver module 30.Other nodes need only make requests of the communication module 32 orthe gateway 142, which will obtain the information from the drivermodule 30 and respond accordingly. Notably, the driver module 30 maymaintain or collect all types of status or performance information forthe lighting fixture 10 and make it available to any device within thelighting fixture 10, on the network via the communication module 32, orto a remote entity via the gateway 142. Further, the master and slavedevices for a given lighting fixture 10 need not be maintained withinthe housing of the lighting fixture 10.

In certain embodiments, the functionality of the communication module 32may be integrated into the driver module 30, or vice versa. Forinstance, the integrated module would have a microcontroller with abuilt in or closely associated radio frequency transceiver, wherein themicrocontroller would provide all of the requisite processing of thedriver module 30 and the communication module 32. The transceiver wouldfacilitate RF communications with other elements (fixtures, sensors,switches, etc.) of the lighting network as well as the commissioningtool 36 and other remote entities. As such, the integrated module couldalso provide the functionality of the gateway 142. The integrated modulecould also include various sensors, such as the ambient light sensorS_(A), the occupancy sensor S_(O), and the like. Any AC-DC conversioncould be provided on the same PCB as the microcontroller and transceiveror may be provided by a remote module or PCB.

Extensive research has been performed in the last few decades onimproving wireless networks in general. However, much of this researchhas focused on reducing power requirements or increasing throughput. Fora lighting system, these priorities should be shifted to increasingresponse time and reducing cost. In a first embodiment, the lightingnodes, such as lighting fixtures 10 and standalone sensors and switches,may be assigned unique addresses starting from the number one. Further,the maximum number of lighting nodes in a given lighting system isbounded at a defined number, such as 256. For the following example,assume that there are six lighting nodes in the lighting network, andeach node is sequentially addressed 1-6. A representation of such alighting network is provided in FIG. 37.

Routing tables are used to identify the next hop along a routing path,and perhaps a number of hops necessary to reach a destination from thecurrent location. An exemplary routing table for lighting node 1,constructed according to related art techniques, is provided immediatelybelow (Table A). For this example, assume that a packet of data needs tobe routed from lighting node 1 to lighting node 6. In the below routingtable, three columns of information are required: the destinationaddress, the next hop address, and the number of hops to the destinationfrom the current location. In operation, the lighting node will identifya destination address for the packet of data being routed, and searchthe destination address field in the routing table to find a match. Ifthe destination address for the packet to be routed is number 6,lighting node 1 will search the entries in the destination address fieldto find one for lighting node 6. The corresponding next hop address (5)for destination address 6 is identified, and the packet of data isrouted to the next hop address (5), wherein the process repeats at eachlighting node until the packet of data reaches its intended destination.

TABLE A Destination Next Hop Number of Address Address Hops 5 5 1 3 2 22 2 1 6 5 3 4 5 2

For the present disclosure, the size of the routing table can be reducedby approximately one third, and thus save on the amount of requiredsystem memory as well as the processing necessary to identify the nexthop address. As shown in the table below (Table B), the column fordestination address is removed. Instead, the routing table isreorganized such that the rows correspond to the destination address. Inother words, the first entry in the routing table corresponds todestination address 1, the second row of the routing table correspondsto destination address 2, the third row in the routing table correspondsto destination address 3, and so on and so forth. Accordingly, and againassuming that the routing table below corresponds to lighting node 1, arouting decision is determined as follows. The destination for thepacket of data is determined. Since the destination address directlycorresponds to the location in the routing table, lighting node 1 needonly access the sixth entry in the routing table to identify the nexthop address for routing a packet of data to destination address 6, whichcorresponds to lighting node 6. Notably, the routing tables arepreferably ordered corresponding to destination address. However, thedestination address does not need to match the position in the routingtable. Offsets and the like may be used to compensate for lightingnetworks or zones that employ lighting nodes that are not associatedwith addresses starting with one. With this embodiment, the size of therouting table is reduced and the amount of processing required tocompare a destination address with various entries in a routing table isreduced. In essence, there is no need to scan through the table to finda matching destination address, because the position in the tablecorresponds to the destination address.

TABLE B Next Hop Number of Address Hops 1 0 2 1 2 2 5 2 5 1 5 3

With reference to FIG. 38, the addresses for the lighting nodes may beassigned based on the lighting zone in which the lighting nodes reside.For example, there are three lighting zones: group 1, group 2, and group3. Lighting nodes 1-6 are in group 1, lighting nodes 7-9 and 11 are ingroup 2, and lighting nodes 10, 12, and 13 are in group 3. Table Ccorresponds to a routing table for lighting node 9 wherein a traditionalrouting table architecture is employed. From analyzing the configurationfor FIG. 38, a large number of the lighting nodes, including all thenodes within group 1, will route through lighting node 8 when routingdata from one group to another. Applicants have discovered that it ismore efficient for lighting node 9 to have two separate sections, whichcorrespond to Table D and Table E below.

TABLE C Destination Next Hop Number of Address Address Hops 6 8 4 2 8 312 10 2 8 8 1 7 8 2 5 8 2 10 10 1 3 8 4 1 8 3 11 11 1 13 10 2 4 8 3

TABLE D Destination Next Hop Number of Group Address Hops 3 10 1 1  8 22 See Next Section

The first section of the routing table for lighting node 9 includesthree fields (or columns): destination group, next hop address, andnumber of hops. This is referred to as the group section. Whendetermining the next hop address, lighting node 9 will identify thegroup in which the destination address resides and use the table todetermine the next hop address for that group destination. Thus, if thedestination address corresponds to 10, 12, or 13 of group 3, the routingtable will identify the next hop address as 10. If the destinationaddress is 1-6, which correspond to group 1, the next hop address forgroup 1, which is destination address 8, is selected and used forrouting the packet of data. Notably, if the destination address residesin the same group, the second section of the routing table is searched.The second section may take the configuration of a traditional routingtable, wherein the destination address is used, such as that shown inTable E below.

TABLE E Destination Next Hop Number of Address Address Hops 7 8 2 11 111 8 8 1

Alternatively, the entire destination address field may be dropped fromthe second section of the routing table. Using the techniques describedin association with FIG. 37, the next hop addresses in the secondsection of the routing table may be positioned in the routing table in aposition corresponding to the destination address. Thus, when the secondsection of the routing table is used, the positioning of the next hopaddress in the routing table will correspond to the actual destinationaddress.

With reference to FIG. 39, yet another routing table configuration isillustrated. The basic configuration of the lighting network shown inFIG. 39 is the same as that of FIG. 38. The only difference is that theaddresses for the respective lighting nodes have been reassigned tofacilitate the creation of very condensed routing tables. An exemplaryrouting table for lighting node 9 is shown below (Table F).

TABLE F Criterion Next Hop Address Destination <9 7 Destination = 10 10Destination >10 11

As illustrated, the routing table only has two fields, and instead ofdetermining the next hop address based on an actual destination addressor a group in which the actual destination address resides, routingcriteria is defined for selecting the next hop address. The routingcriteria are based on a range in which the destination addresses fall,and in certain instances, the actual destination address. For example,and again using lighting node 9, the next hop address for anydestination address less than 9 is destination address 7. The next hopaddress for any destination address greater than 10 is destinationaddress 11. Finally, if the destination address is 10, the next hop isdestination address 10. This embodiment illustrates the concept ofassigning addresses to the various lighting nodes within the individualzones (or groups) and the overall system as a whole, with an eye towardthe routing tables. With routing tables in mind, addresses may beassigned to the various lighting nodes in a manner that greatly reducesthe number of entries in the routing tables, and wherein at leastcertain next hop address selections are based on a range in which thedestination address falls. These improvements in routing may be used invirtually any networking scheme, and are not limited solely to lightingapplications.

While the embodiments described above were focused on a troffer-typelighting fixture 10, the concepts disclosed herein apply to any type oflighting fixture. For example, a recessed-type lighting fixture 10′ asillustrated in FIG. 40 may also incorporate all of the conceptsdescribed above. As illustrated, the lighting fixture 10′ includes amain housing 12′, a lens 14′, and an electronics housing 26′. Thevarious modules described above may be housed within the electronicshousing 26′ or attached thereto, outside of or within supplementalplenum rated enclosures. These configurations will vary based on theparticular application. However, the concepts of a modular system thatallows any of the modules to be readily replaced and new modules addedare considered to be within the scope of the present disclosure and theclaims that follow.

The present disclosure relates to a lighting network where control ofthe lighting fixtures in the network may be distributed among thelighting fixtures. The lighting fixtures may be broken into groups thatare associated with different lighting zones. At least some of thelighting fixtures will have or be associated with one or more sensors,such as occupancy sensors, ambient light sensors, and the like. Withinthe overall lighting network or the various lighting zones, the lightingfixtures may share sensor data from the sensors. Each lighting fixturemay process sensor data provided by its own sensor, a remote standalonesensor, or lighting fixture, and process the sensor data according tothe lighting fixture's own internal logic to control operation of thelighting fixture. The lighting fixtures may also receive control inputfrom other lighting fixtures, control nodes, light switches, andcommissioning tools. The control input may be processed along with thesensor data according to the internal logic to further enhance controlof the lighting fixture.

Accordingly, control of the lighting network of the present disclosureis decentralized so that each lighting fixture essentially operatesindependently of the lighting network; however, the internal logic ineach of the lighting fixtures is configured so that the lightingfixtures may act in concert as a group. While acting in concert, eachlighting fixture may operate in a different manner depending on thegoals for the particular lighting application. The lighting fixtures mayalso respond to any user inputs that are presented.

In one embodiment, a lighting fixture having a light sensor, asolid-state light source, and associated circuitry is provided. Thecircuitry is adapted to determine that a given lighting fixture of aplurality lighting fixtures is entering a lightcast mode. Via the lightsensor, the circuitry will monitor for a first lightcast signal providedby the given lighting fixture and effect generation of grouping data forthe given lighting fixture based on receipt of the first lightcastsignal. The grouping data may be used, at least in part, for groupingthe lighting fixture with one or more of the plurality of lightingfixtures. For grouping the lighting fixture with one or more of theplurality of lighting fixtures, the circuitry may send the grouping datato a remote entity, which will determine how to group the plurality oflighting fixtures, and receive information identifying a group to whichthe lighting fixture belongs. Alternatively, the circuitry may send thegrouping data to one of the plurality of lighting fixtures that willdetermine how to group the plurality of lighting fixtures.

For grouping the lighting fixture with one or more of the plurality oflighting fixtures, the circuitry may process the grouping data alongwith other grouping data received from one or more of the pluralitylighting fixtures to determine a group of the plurality of lightingfixtures in which the lighting fixture belongs. If the first lightcastsignal is detected, the grouping data may be indicative of a relativesignal strength of the lightcast signal.

In another embodiment, the circuitry may be adapted to enter thelightcast mode and then drive the solid-state light source to provide asecond lightcast signal to be monitored by the plurality of lightingfixtures. In advance of providing the lightcast signal, the circuitrymay send, to the plurality of lighting fixtures, an instruction to beginmonitoring for the second lightcast signal.

The circuitry may be further adapted to receive remote sensor data fromat least one of the plurality of lighting fixtures and drive thesolid-state light source based on the remote sensor data. As such, thecircuitry may determine local sensor data from the light sensor oranother local sensor of the lighting fixture and drive the solid-statelight source based on both the remote sensor data and the local sensordata. The circuitry may also send the local sensor data to at least oneof the plurality of lighting fixtures.

The circuitry may also identify a group of the plurality of lightingfixtures to which the lighting fixture has been assigned and drive thesolid-state light source in response to an instruction intended for thegroup. Each lighting fixture may be assigned to just one group or may beassigned to multiple groups in the case of overlapping groups, whichshare at least one lighting fixture.

The circuitry may be split into a driver module that is adapted to drivethe solid-state light source and a communications module that is adaptedto communicate with the plurality of lighting fixtures and control thedriver module. The driver module and the communications modulecommunicate with one another over a communications bus.

In yet another embodiment, a lighting network is provided with aplurality of lighting fixtures having associated light sensors. During amonitor mode, each of the plurality of lighting fixtures is adapted todetermine that a given lighting fixture of the plurality lightingfixtures is entering a lightcast mode; via the light sensor, monitor fora lightcast signal provided by the given lighting fixture; and effectgeneration of grouping data for the given lighting fixture based onreceipt of the first lightcast signal. During a receive mode, eachlighting fixture will drive an associated solid-state light source toprovide the lightcast signal for monitoring by others of the pluralityof lighting fixtures. Each of the plurality of lighting fixtures may beautomatically assigned to at least one of a plurality of groups based onthe grouping data.

The grouping data associated with any two of the plurality of lightingfixtures may indicate a relative magnitude of the lightcast signal,which was provided by a first of the two, and received by a second ofthe two. Further, each of the plurality of lighting fixtures may beadapted to exchange the grouping data that is gathered for others of theplurality of lighting fixtures and automatically assign itself to one ofa plurality of groups based on the grouping data, such that each of theplurality of groups comprises those lighting fixtures that were able todetect the lightcast signal from other lighting fixtures in theparticular group. Alternatively, each of the plurality of lightingfixtures may be adapted to exchange the grouping data that is gatheredfor others of the plurality of lighting fixtures and automaticallyassign itself to one of a plurality of groups based on the groupingdata, such that each of the plurality of groups comprises those lightingfixtures that were able to detect, at a magnitude above a set threshold,the lightcast signal from other lighting fixtures in the particulargroup.

The grouping data gathered by each of the plurality of lighting fixturesmay be sent to a remote entity, which assigns the plurality of lightingfixtures to groups based on the grouping data. The grouping datagathered by each of the plurality of lighting fixtures may also be sentto one of the plurality of lighting fixtures, which assigns theplurality of lighting fixtures to groups based on the grouping data.

Also, each lighting fixture may be adapted to share sensor data from itslight sensor or another associated sensor with others of the pluralityof lighting fixtures, and control light output based on the sensor datain light of its own internal logic. The internal logic may be configuredsuch that each of the plurality of lighting fixtures operatesindependently from one another while providing light in a concertedfashion.

In yet another embodiment, a lighting network is provided with a groupof lighting fixtures, which have sensors and solid-state light sources.Each lighting fixture of the group of lighting fixtures may be adaptedto coordinate with at least one of the of the group of lighting fixturesto determine a light output level, and drive the solid-state lightsources to provide the light output. At least certain of the group oflighting fixtures will concurrently provide a different light outputlevel. Different subgroups of the group of lighting fixtures may providedifferent light output levels or output levels that are graduated amongthe group of lighting fixtures. The light output level for each lightingfixture may be determined, at least in part, on ambient light. Theamount of ambient light may be detected via the light sensor of thelighting fixture. Notably, the light output level for each lightingfixture may be determined, at least in part, on an amount of ambientlight detected via a light sensor of another lighting fixture of thegroup of lighting fixtures.

Each of the plurality of lighting fixtures, including the group oflighting fixtures, may be adapted to determine that a given lightingfixture of the plurality of lighting fixtures is entering a lightcastmode; via the light sensor, monitor for a lightcast signal provided bythe given lighting fixture; and effect generation of grouping data forthe given lighting fixture based on receipt of the first lightcastsignal. Each of the plurality of lighting fixtures may drive anassociated solid-state light source to provide the lightcast signal formonitoring by others of the plurality of lighting fixtures. Each of theplurality of lighting fixtures may be automatically assigned to at leastone of a plurality of groups based on the grouping data.

The present disclosure relates to a lighting network where control ofthe lighting fixtures in the network may be distributed among thelighting fixtures. The lighting fixtures may be broken into groups thatare associated with different lighting zones. At least some of thelighting fixtures will have or be associated with one or more sensors,such as occupancy sensors, ambient light sensors, and the like. Withinthe overall lighting network or the various lighting zones, the lightingfixtures may share sensor data from their sensors. Each lighting fixturemay process sensor data provided by its own sensor, a remote standalonesensor, or lighting fixture, and process the sensor data according tothe lighting fixture's own internal logic to control operation of thelighting fixture. The lighting fixtures may also receive control inputfrom other lighting fixtures, control nodes, light switches,commissioning tools, gateways, and remote devices via the Internet orother like network. The control input may be processed along with thesensor data according to the internal logic to further enhance controlof the lighting fixture.

Accordingly, control of the lighting network of the present disclosuremay be decentralized so that each lighting fixture essentially operatesindependently of the lighting network; however, the internal logic ineach of the lighting fixtures is configured so that the lightingfixtures may act in concert as a group. While acting in concert, eachlighting fixture may operate in a different manner, such as providingdifferent light output levels, depending on the goals for the particularlighting application. The lighting fixtures may also respond to any userinputs that are presented.

In one embodiment, each lighting fixture includes a solid-state lightsource and circuitry to control operation. In particular, the circuitryis adapted to receive remote sensor data from at least one otherlighting fixture and drive the solid-state light source based on theremote sensor data. The lighting fixture may include a local sensor,such as an ambient lighting sensor, occupancy sensor, or the like. Withthe local sensor, the circuitry is further adapted to determine localsensor data from the local sensor and drive the solid-state light sourcebased on both the remote sensor data and the local sensor data. Thelocal sensor data may also be sent to other lighting fixtures, which mayuse the local sensor data to help control those lighting fixtures. Inaddition to controlling the lighting fixtures, sensor activity can showuse patterns in fine detail. Some examples would be occupancy sensorpatterns within a room showing what areas are used in a room over anextended time period, or the ambient light sensors showing howefficiently daylight is being captured and distributed from the windowsto the room.

As such, these lighting fixtures may share their sensor data with otherlighting fixtures in a lighting network and control their light outputbased on the local and remote sensor data in view of their own internallogic. The internal logic is configured such that each of the lightingfixtures operates independently from one another while providing lightor functionality in a concerted fashion.

For example, a switch may be used to turn on all of the lightingfixtures in a particular zone. However, the amount of light provided bythe various lighting fixtures may vary from one lighting fixture to thenext based on the amount of ambient light present in the different areasof the lighting zone. The lighting fixtures closer to windows mayprovide less light or light of a different color or color temperaturethan those lighting fixtures that are near an interior wall.

The present disclosure relates to a lighting network where control ofthe lighting fixtures in the network may be distributed among thelighting fixtures. The lighting fixtures may be broken into groups thatare associated with different lighting zones. At least some of thelighting fixtures will have or be associated with one or more sensors,such as occupancy sensors, ambient light sensors, and the like. Withinthe overall lighting network or the various lighting zones, the lightingfixtures may share sensor data from their sensors. Each lighting fixturemay process sensor data provided by its own sensor, a remote standalonesensor, or lighting fixture, and process the sensor data according tothe lighting fixture's own internal logic to control operation of thelighting fixture. The lighting fixtures may also receive control inputfrom other lighting fixtures, control nodes, light switches, andcommissioning tools. The control input may be processed along with thesensor data according to the internal logic to further enhance controlof the lighting fixture.

Accordingly, control of the lighting network of the present disclosuremay be decentralized so that each lighting fixture essentially operatesindependently of the lighting network; however, the internal logic ineach of the lighting fixtures is configured so that the lightingfixtures may act in concert as a group. While acting in concert, eachlighting fixture may operate in a different manner, such as providingdifferent light output levels, depending on the goals for the particularlighting application. The lighting fixtures may also respond to any userinputs that are presented.

In such a lighting system, the lighting fixtures need to communicateinformation between them, and in many instances, route information inthe form of data packets from one lighting fixture to another. As such,the lighting fixtures may generate data packets and route them toanother lighting fixture, which may process the information in the datapacket or route the data packet toward another lighting fixture.

In a first embodiment, each lighting fixture includes a light source andcircuitry to control operation. For providing light output, thecircuitry is adapted to drive the lighting source to provide lightoutput. For routing data packets, the circuitry employs a routing tablehaving a next hop address for each of a plurality of destinationaddresses. Each next hop address is positioned in the routing tablebased on a corresponding one of the plurality of destination addresses.As such, the plurality of destination addresses need not be used toaccess the routing table.

The circuitry may first determine a position in the routing table basedon a destination address of the data packet. Next, the next hop addressfor the destination address is accessed based on the position in therouting table; and then the data packet is routed toward the next hopaddress. In essence, the next hop address for each of the plurality ofdestination addresses may be positioned in the routing table in an ordercorresponding to a numerical ordering of the plurality of destinationaddresses. To access the next hop address for the destination address,the circuitry may use the destination address as an index to identifythe next hop address for the destination address from the routing table.The routing table may include a number of hops for each next hopaddress. The number of the plurality of nodes may correspond to a numberof positions in the routing table. In one scenario, a value of eachdestination address directly corresponds to a position that contains acorresponding next hop address in the routing table.

In a second embodiment, the routing table is broken into at least afirst section and a second section. The first section includes a nexthop address for each of a plurality of groups of lighting fixtures towhich the lighting fixture does not belong. The second section comprisesa next hop address corresponding to each of a plurality of destinationaddresses associated with a group of lighting fixtures to which thelighting fixture belongs.

In one implementation, the second section comprises each of theplurality of destination addresses in association with the correspondingnext hop address. The next hop address is accessed based directly on thecorresponding destination address. In another implementation, each nexthop address is positioned in the routing table based on a correspondingone of the plurality of destination addresses such that the plurality ofdestination addresses are not used to access the routing table.

If the data packet is intended for one of the plurality of groups oflighting fixtures to which the lighting fixture does not belong, thecircuitry will access the first section and determine the next hopaddress based on the one of the plurality of groups of lighting fixturesto which the lighting fixture does not belong. If the data packet isintended for the group of lighting fixtures to which the lightingfixture belongs, the circuitry will access the second section todetermine the next hop address for the data packet. Once the next hopaddress is identified, the circuitry will route the data packet towardthe next hop address.

In a third embodiment, a lighting fixture comprising routing criteria isprovided that has a next hop address for each of at least two ranges ofdestination addresses. When routing a data packet toward one of the atleast two ranges of destination addresses, the circuitry will firstdetermine a destination address for the data packet. Next, the circuitrywill select a next hop address from the routing criteria based on one ofthe at least two ranges of destination addresses in which thedestination address falls; and then route the data packet toward thenext hop address. The routing criteria may also include a next hopaddress for at least one destination address. If the next hop address isdirectly associated with a destination address instead of a range ofaddresses, the circuitry will determine a destination address for thedata packet, select a next hop address from the routing criteria basedon the at least one destination, and route the data packet toward thenext hop address.

The present disclosure relates to a lighting network where control ofthe lighting fixtures in the network may be distributed among thelighting fixtures. The lighting fixtures may be broken into groups thatare associated with different lighting zones. At least some of thelighting fixtures will have or be associated with one or more sensors,such as occupancy sensors, ambient light sensors, and the like. Withinthe overall lighting network or the various lighting zones, the lightingfixtures may share sensor data from their sensors. Each lighting fixturemay process sensor data provided by its own sensor, a remote standalonesensor, or lighting fixture, and process the sensor data according tothe lighting fixture's own internal logic to control operation of thelighting fixture. The lighting fixtures may also receive control inputfrom other lighting fixtures, control nodes, light switches, andcommissioning tools. The control input may be processed along with thesensor data according to the internal logic to further enhance controlof the lighting fixture.

Accordingly, control of the lighting network of the present disclosuremay be decentralized so that each lighting fixture essentially operatesindependently of the lighting network; however, the internal logic ineach of the lighting fixtures is configured so that the lightingfixtures may act in concert as a group. While acting in concert, eachlighting fixture may operate in a different manner, such as providingdifferent light output levels, depending on the goals for the particularlighting application. The lighting fixtures may also respond to any userinputs that are presented.

In one embodiment, a handheld device may be used to setup, configure,and control the various lighting fixtures through wired or wirelesscommunications means once the lighting fixtures are installed in alighting network. The handheld device may be used to configure theinternal logic of the various lighting fixtures to operate in a desired,coordinated fashion; assign the lighting fixtures to groups associatedwith defined lighting zones; reassign the lighting fixtures to othergroups, and the like. For grouping, the handheld device may beconfigured to receive grouping data from the various lighting fixturesand group the lighting fixtures based on the grouping data. Once thegroups have been determined, the handheld device may inform eachlighting fixture of the group or groups to which the lighting fixturehas been assigned.

The present disclosure relates to a lighting fixture that includes adriver module and at least one other module that provides a lightingfixture function, such as a sensor function, lighting networkcommunication function, gateway function, and the like. The drivermodule communicates with the other modules in a master/slave scheme overa communication bus. The driver module is configured as a slavecommunication device, and the other modules are configured as mastercommunication devices. As such, the other modules may initiatecommunications with the driver to send information to or retrieveinformation from the driver module.

In one embodiment, a lighting fixture is provided that includes a drivermodule and a communications module. The driver module is adapted todrive an associated light source and to facilitate communications over acommunication bus as a slave communication device. The communicationsmodule is adapted to facilitate wireless communications with otherelements in a lighting network and communicate as a master communicationdevice with the driver module over the communication bus. The lightingfixture may also include an auxiliary module adapted to provide alighting fixture function for the lighting fixture as well as facilitatecommunications as a master communication device with the driver moduleover the communication bus. Being master communication devices, both theauxiliary device and the communications module may initiatecommunications with the driver module. The driver module may be adaptedto receive AC power and provide DC power to the communications moduleand the auxiliary module. The communication bus may be a serialcommunication bus, such as an I²C bus.

Communications with the driver module may include requesting informationfrom the driver module and transferring information to the drivermodule. The auxiliary module may be configured to have 1) an occupancysensor wherein the lighting fixture function is detecting occupancy, 2)an ambient light sensor wherein the lighting fixture function isdetecting ambient light, and 3) a communication gateway wherein thelighting fixture function is providing a wireless communication gatewayto at least one of a remote device and a network outside of the lightingnetwork.

In one scenario, the communications module is adapted to wirelesslyreceive first information from one of the other elements of the lightingnetwork and, as the master communication device, initiate transfer ofthe first information to the driver module, which will control the lightsource based on the first information. Further, the auxiliary module mayinclude a sensor and be adapted to determine second information bearingon an output of the sensor. As the master communication device, theauxiliary module may initiate transfer of the second information to thedriver module, which will control the light source based on the secondinformation.

The communications module may be adapted to wirelessly receiveinformation from one of the other elements of the lighting network and,as the master communication device, initiate transfer of the informationto the driver module, which will control the light source based on thisinformation.

The driver module may be further adapted to communicate with a remoteswitch via the communication bus, wherein the remote switch is alsoconfigured as a master communication device, which is adapted toinitiate transfer of switch information to the driver module, which willcontrol the light source based on the switch information.

The present disclosure relates to lighting fixtures for use in alighting network where the lighting fixtures and other elements are ableto communicate with each other via wired or wireless communicationtechniques. When the lighting network is being formed or modified, thelighting fixtures may be able to communicate with each other andautomatically determine a single lighting fixture to act as acoordinator during a commissioning process. In essence, the lightingfixtures can exchange their communication addresses, such as MACaddresses, wherein the lighting fixture with the lowest (or highest)normal communication address becomes the coordinator. The coordinatormay also be configured to assign short addresses to use forcommunications once the lighting network is formed instead of the longerMAC, or like, addresses. The short addresses can reduce routingoverhead, and thus make the routing of messages including controlinformation, sensor data, and the like, more efficient.

In one exemplary embodiment, a lighting fixture is provided that has afirst address and is intended to be employed in a lighting network withany number of elements. The lighting fixture generally includes a lightsource, a communication interface, and circuitry for controlling thelighting fixture. In addition to controlling the light source, thecircuitry is adapted to receive from a first remote lighting fixture afirst ‘join my network’ message, which includes a second address for thefirst remote lighting fixture. The circuitry will compare the firstaddress with the second address. If the first address does not have apredefined relationship with the second address, the circuitry mayrecognize the first remote lighting fixture as the coordinator for thelighting network. If the first address has the predefined relationshipwith the second address, the circuitry may set its own lighting fixtureas the coordinator for the lighting network. The predefined relationshipmay simply be whether the first address is higher or lower than thesecond address; however, the concepts disclosed herein are not limitedto these two relationships.

If short addresses are to be used, the circuitry may generate a shortaddress for the first remote lighting fixture and send the short addressto the first remote lighting fixture, if the first address has thepredefined relationship with the second address. In this case, thelighting fixture will, at least temporarily, consider itself thecoordinator for the first remote lighting fixture. Again, the firstshort address is shorter than the first address. For example the firstaddress may be a 64-bit MAC address, and the short address may be an 8,16, or 24-bit address or the like. The circuitry will send the firstshort address to the first remote lighting fixture. If the first addressdoes not have the predefined relationship with the second address, thecircuitry may wait to receive a first short address for the lightingfixture to use for communications within the lighting network, whereinthe first short address is shorter than the first address.

The lighting fixture may receive ‘join my network’ messages fromdifferent lighting fixtures during the commissioning process. Thelighting fixture may initially think it is the coordinator relative toone remote lighting fixture during a first exchange and the then give upits coordinator role during a second exchange with another remotelighting fixture. For example, the circuitry may be adapted to receivefrom a second remote lighting fixture a second ‘join my network’ messageincluding a third address for the second remote lighting fixture, andcompare the first address with the third address. If the first addressdoes not have the predefined relationship with the third address, thecircuitry may recognize the first remote lighting fixture as thecoordinator for the lighting network. If the first address has thepredefined relationship with the third address, the circuitry may setits own lighting fixture as the coordinator, at least temporarily, forthe lighting network.

When the lighting fixtures are mostly routing nodes for a mesh network,the circuitry for the lighting fixture that ultimately becomes thecoordinator may assign short addresses to each of the non-routingelements, which may include sensor modules, switch modules, certainlighting fixtures, and the like in the lighting network.

The circuitry for the coordinator may effect delivery of instructions tothe various elements, both routing and non-routing, to initiate agrouping process, wherein the elements coordinate with each other toform a plurality of groups of elements. The grouping process may employlightcasting processing wherein as one element emits a lightcast signal,other ones of the elements monitor the lightcast signal to determinelightcast data that is used determine the plurality of groups ofelements. One or more elements, such as a coordinator, may collect thelightcast data from the other ones of the elements as well as send tothe other ones of the elements information that identifies a group towhich each of the ones of the elements are assigned. The coordinator mayactually determine the groups or use a remote entity, such as acommissioning tool or other control system, to determine the groups.Alternatively, certain of the elements may exchange all of the data andindependently identify themselves with a group.

The present disclosure relates to lighting fixtures for use in alighting network where the lighting fixtures and other elements are ableto communicate with each other via wired or wireless communicationtechniques. When the lighting network is being formed or modified, alighting fixture is selected to act as a coordinator for forming thelighting network. For example, a user may employ a commissioning tool toselect a particular lighting fixture as the coordinator. The coordinatorwill send out one or more ‘join my network’ messages toward the otherelements of the lighting network. The elements that receive the ‘join mynetwork’ message may respond in order to make the coordinator aware oftheir presence and join them to a lighting network.

In certain embodiments, the coordinator will assign short addresses toitself and to the other elements in the lighting network. While theelements already have MAC or like addresses, once the short addressesare assigned, the elements of the routing network will use the shortaddresses for normal communications. The short addresses can reducerouting overhead, and thus make the routing of messages includingcontrol information, sensor data, and the like, more efficient.

The lighting network may be a mesh network formed from the variouselements wherein some elements act as routing nodes and other elementsact as non-routing nodes. For example, some or all of the lightingfixtures may be routing nodes while switches, stand-alone sensors, andthe like may be non-routing nodes in select embodiments. However, thereis no limitation as to whether a particular type of element can beconfigured as a routing or non-routing element.

The coordinator may effect delivery of instructions to the variouselements, both routing and non-routing, to initiate a grouping process,wherein the elements coordinate with each other to form a plurality ofgroups of elements. The grouping process may employ lightcastingprocessing wherein as one element emits a lightcast signal, other onesof the elements monitor the lightcast signal to determine the pluralityof groups of elements. One or more elements, such as a coordinator, maycollect the lightcast data from the other ones of the elements as wellas send information to the other ones of the elements that identifies agroup to which each of the ones of the elements are assigned. Thecoordinator may actually determine the groups or it may use a remoteentity, such as a commissioning tool or other control system, todetermine the groups. Alternatively, certain of the elements mayexchange all of the data and independently identify themselves with agroup.

Those skilled in the art will recognize improvements and modificationsto the embodiments of the present disclosure. All such improvements andmodifications are considered within the scope of the concepts disclosedherein and the claims that follow.

What is claimed is:
 1. A lighting fixture comprising: a light sensor; alight source; and circuitry adapted to: determine that a given lightingfixture of a plurality of lighting fixtures is entering a lightcastmode, in which the given lighting fixture emits a first lightcast signalvia a light source of the given lighting fixture to group lightingfixtures; via the light sensor, monitor for the first lightcast signalprovided by the given lighting fixture; and effect generation ofgrouping data for the given lighting fixture based on receipt of thefirst lightcast signal.
 2. The lighting fixture of claim 1 wherein thegrouping data is used, at least in part, for grouping the lightingfixture with one or more of the plurality of lighting fixtures.
 3. Thelighting fixture of claim 2 wherein, for grouping the lighting fixturewith one or more of the plurality of lighting fixtures, the circuitry isadapted to send the grouping data to a remote entity, which willdetermine how to group the plurality of lighting fixtures, and receiveinformation identifying a group to which the lighting fixture belongs.4. The lighting fixture of claim 2 wherein, for grouping the lightingfixture with one or more of the plurality of lighting fixtures, thecircuitry is adapted to send the grouping data to one of the pluralityof lighting fixtures that will determine how to group the plurality oflighting fixtures.
 5. The lighting fixture of claim 2 wherein, forgrouping the lighting fixture with one or more of the plurality oflighting fixtures, the circuitry is adapted to process the grouping dataalong with other grouping data received from one or more of theplurality of lighting fixtures to determine a group of the plurality oflighting fixtures in which the lighting fixture belongs.
 6. The lightingfixture of claim 1 wherein the circuitry is further adapted to: enterthe lightcast mode; drive the light source to provide a second lightcastsignal to be monitored by the plurality of lighting fixtures.
 7. Thelighting fixture of claim 6 wherein the circuitry is further adapted tosend, to the plurality of lighting fixtures, an instruction to beginmonitoring for the second lightcast signal.
 8. The lighting fixture ofclaim 1 wherein, if the first lightcast signal is detected, the groupingdata is indicative of a relative signal strength of the first lightcastsignal.
 9. The lighting fixture of claim 1 wherein the circuitry isfurther adapted to: receive remote sensor data from at least one of theplurality of lighting fixtures; and drive the light source based on theremote sensor data.
 10. The lighting fixture of claim 9 wherein: thecircuitry is further adapted to determine local sensor data from thelight sensor or another local sensor of the lighting fixture; and thelight source is driven by the circuitry based on both the remote sensordata and the local sensor data.
 11. The lighting fixture of claim 10wherein the circuitry is further adapted to send the local sensor datato at least one of the plurality of lighting fixtures.
 12. The lightingfixture of claim 9 wherein: the circuitry is further adapted to:determine local sensor data from the light sensor or another localsensor of the lighting fixture; and send the local sensor data to atleast one of the plurality of lighting fixtures.
 13. The lightingfixture of claim 1 wherein the circuitry comprises: a driver module thatis adapted to drive the light source; and a communications module thatis adapted to communicate with the plurality of lighting fixtures andcontrol the driver module.
 14. The lighting fixture of claim 13 whereinthe driver module and the communications module communicate with oneanother over a communications bus.
 15. The lighting fixture of claim 1wherein the circuitry is further adapted to identify a group of theplurality of lighting fixtures to which the lighting fixture has beenassigned and drive the light source in response to an instructionintended for the group.
 16. The lighting fixture of claim 1 wherein thecircuitry is further adapted to identify at least two groups of theplurality of lighting fixtures to which the lighting fixture has beenassigned and drive the light source in response to instructions intendedfor the at least two groups.
 17. The lighting fixture of claim 1 whereinthe light source is a solid-state light source.
 18. A lighting networkcomprising a plurality of lighting fixtures that have light sensors andeach of the plurality of lighting fixtures is adapted to: during amonitor mode: determine that a given lighting fixture of the pluralityof lighting fixtures is entering a lightcast mode; via the light sensor,monitor for a lightcast signal provided by the given lighting fixture;and effect generation of grouping data for the given lighting fixturebased on receipt of the lightcast signal; and during a receive mode,drive an associated light source to provide the lightcast signal formonitoring by others of the plurality of lighting fixtures to group thelighting fixtures.
 19. The lighting network of claim 18 wherein each ofthe plurality of lighting fixtures is automatically assigned to at leastone of a plurality of groups based on the grouping data.
 20. Thelighting network of claim 19 wherein the grouping data associated withany two of the plurality of lighting fixtures indicates whether thelightcast signal provided by a first of the two was received by a secondof the two.
 21. The lighting network of claim 19 wherein the groupingdata associated with any two of the plurality of lighting fixturesindicates a relative magnitude of the lightcast signal provided by afirst of the two and received by a second of the two.
 22. The lightingnetwork of claim 18 wherein each of the plurality of lighting fixturesis adapted to exchange the grouping data that is gathered for others ofthe plurality of lighting fixtures and automatically assign itself to aparticular group of a plurality of groups based on the grouping data,such that each of the plurality of groups comprises those lightingfixtures that were able to detect the lightcast signal from otherlighting fixtures in the particular group.
 23. The lighting network ofclaim 18 wherein each of the plurality of lighting fixtures is adaptedto exchange the grouping data that is gathered for others of theplurality of lighting fixtures and automatically assign itself to aparticular group of a plurality of groups based on the grouping data,such that each of the plurality of groups comprises those lightingfixtures that were able to detect, at a magnitude above a set threshold,the lightcast signal from other lighting fixtures in the particulargroup.
 24. The lighting network of claim 18 wherein the grouping datagathered by each of the plurality of lighting fixtures is sent to aremote entity, which assigns the plurality of lighting fixtures togroups based on the grouping data.
 25. The lighting network of claim 18wherein the grouping data gathered by each of the plurality of lightingfixtures is sent to one of the plurality of lighting fixtures, whichassigns the plurality of lighting fixtures to groups based on thegrouping data.
 26. The lighting network of claim 18 wherein eachlighting fixture is further adapted to: share sensor data from the lightsensor or another associated sensor with others of the plurality oflighting fixtures; and control light output based on the sensor data inview of its own internal logic, wherein the internal logic is configuredsuch that each of the plurality of lighting fixtures operatesindependently from one another while providing light in a concertedfashion.
 27. The lighting network of claim 18 wherein the light sourceis a solid-state light source.